When the hijackers of Egyptair Flight 648 systematically began shooting American and Israeli passengers at 10-minute intervals last Sunday night, they triggered a reaction that led to the loss of nearly 60 lives, one of the bloodiest hostage-rescue attempts on record.

The hijacking and its aftermath mark another twist in the rising spiral of terror and counterterror in the Middle East, this time adding a particularly chilling prospect: blind terrorism with no demands, terrorism as an end in itself.

And the victims, with increasing frequency, are Americans -- for no apparent reason other than that they are Americans. In both the Achille Lauro and TWA hijackings earlier this year, hijackers also singled out American passengers as their victims.

"What worries me," said one senior European diplomat in Valletta, Malta, who asked not to be identified, "is that once the general international taboo on murder of hostages has been breached, then there is less resistance to it by those who follow with their own hijackings or hostage-takings. Once murder happens, it becomes somehow acceptable to the hijackers to continue doing it.

"Whatever civilized bounds once inhibited hijackers and kidnapers from coldblooded murder seem to have broken down."

The Egyptair disaster -- the third major hijacking since mid-June -- differs markedly from the TWA and Achille Lauro hijackings in that it has left many more than the usual number of questions unanswered.

*The identity of the hijackers, how they smuggled their weapons aboard and what their intentions were, still are not clear.

*The Egyptian rescue attempt, which led to all but two or three of the deaths, has come under fire from some witnesses and the Greek government. Greece has blamed the government of Egyptian President Hosni Mubarak for the deaths; Egypt contends that the deaths were caused by the hijackers.

The Boeing 737, with 92 passengers and six crew aboard, was hijacked shortly after it left Athens for Cairo and diverted to the Mediterranean island nation of Malta Nov. 23.

Passengers who survived the ordeal of Flight 648 say it began about 20 minutes after the plane left Athens, when one hijacker, presumed to be the leader, forced his way into the cockpit and two others stepped into the aisles, brandishing grenades and pistols. The masked hijackers shouted in Arabic: "Don't move!"

The hijackers then frisked the passengers and collected their passports. One passenger, an Egyptian air marshal, pulled a gun, shooting and killing one of the hijackers. The two remaining hijackers opened fire on the security guard, wounding him. Several passengers were wounded in the midair shoot-out, which damaged the plane and caused the cabin to lose air pressure, releasing oxygen masks.

In the cockpit, pilot Hani Galal said he would have to make an emergency landing in Malta, and the hijackers' leader asked whether the plane could make it to Libya, instead. Copilot Emad Bahey Monib told the hijacker that it couldn't and that it would crash into the sea unless it put down in Malta. The hijacker agreed.

After landing on a darkened runway at Malta's Luqa International Airport, the hijackers requested fuel, an ambulance and a doctor. The control tower, where Maltese Prime Minister Carmelo Mifsud Bonnici and Cabinet officials had gathered even before the plane landed, responded that the passengers would have to be released before fuel was provided.

The hijackers released two wounded flight attendants and the wounded security guard. They then began calling for women by nationality, ostensibly to release them. They allowed 11 women -- three Egyptians and eight Filipinos -- to leave the plane.

"They said that all Egyptian women could go free, all Filipino women could go free, all Greek women and all Israeli women," passenger Tony Lyons, 36, an Australian, told The Associated Press. "And as the Israeli girl got up and got to the steps of the plane, they shot her."

Tamar Artzi, 23, of Revivim, Israel, was the first passenger the hijackers shot.

After a hijacker shoved her out the plane's door and fired a bullet into her head, she found herself at the bottom of the steps, stunned.

"I was just thinking it wasn't so bad," she said, when she was shot again, this time in the right hip. She crawled under the steps and stayed there, "afraid to move again because he might see me."

After Artzi was pushed out of the plane, the hijackers, again demanding fuel, warned that they would kill more passengers, beginning in 10 minutes and every 10 minutes after that.

By now, according to passengers' accounts, the hijackers had sorted passports by nationality and seated the passengers accordingly, picking out Israelis and Americans as their first and second choices for victims, other westerners next, then Filipinos. Arabs were last, in the rear of the plane.

The next victim was another Israeli woman, Nitzan Mendelson, 23, who was traveling with Artzi. She has been declared brain dead.

The third was Patrick Scott Baker, 28, of White Salmon, Wash., who was grazed by a bullet in the back of the head.

"Five or 10 minutes went by and then they went through the passports again, and they called for the three Americans," Baker said. "I stepped out, followed by two women.

"At the front of the cabin, my hands were bound by a necktie tied by one of the passengers that had been forced to help the hijackers. He was reluctant. He apologized and said he was sorry. He bound the hands of the girls, and we were sat in the front seat of the starboard side."

After the hijacker shot him, Baker said, he escaped by playing dead until he felt it was safe to dash under the plane, out of sight of the hijackers.

The hijackers' leader, who called himself Nabil, was described by pilot Galal as singing, dancing and joking after each shooting. "He was not touched by the killings," Galal said.

The fourth victim in the deadly lottery was the only American to die in the crisis: Scarlett Marie Rogenkamp, 38, of Oceanside, Calif., a civilian employe of the Air Force.

Jackie Nink Pflug, 30, of Pasadena, Tex., was the last person the hijackers shot before Egyptian commandos stormed the plane after night fell Sunday. She was flown to an Army hospital in Landstuhl, West Germany, Friday and was reported in good condition yesterday. She had been shot in the head; the bullet stopped at the skull.

The Egyptian rescue operation, which has been the focus of much recrimination because of the massive loss of life, began with the arrival Sunday morning of a C130 Egyptian Air Force transport with a squad of Egyptian commandos under the command of Maj. Gen. Mohammed Kamal Din.

After the Maltese prime minister gave the Egyptians the green light at about 8 p.m., approximately 25 commandos stormed the plane, using a powerful explosive to blow a hole in a cargo hold below the rear of the cabin -- the area where the hijackers had consigned the Arab passengers -- and pushing out emergency doors over the wings to gain entry.

Mohammed Wakil, 33, an Egyptian cooking instructor at a Libyan hotel school, was sitting by one of the wing emergency exits when the assault began. He said he recalled seeing Egyptian soldiers crawling along the wing, then pushing open the emergency hatch about the time of the initial explosion and charging into the cabin.

"The Egyptian soldier threw a gas bomb and before that the terrorists threw a grenade. I heard one grenade, then the Egyptian gas bomb."

Wakil, who was wounded in a hand and a leg by the commandos after he leaped from the plane, said, "I told them in Egyptian, 'I'm a passenger, don't shoot any more.' "

Of the 98 passengers (including hijackers) and crew aboard Flight 648 when it left Cairo, at least 57 died in the rescue attempt. Two, Rogenkamp and one hijacker, were killed before the operation began; 14 were released; 4 were wounded and pushed out of the plane. One other victim, Pablito Sumiran, 26, of the Philippines, was killed under circumstances that are still unclear. At most, the Egyptians rescued 20.

The Maltese government is conducting an investigation into the cause of death of the passengers. Initial autopsy reports indicate that most of them died of smoke inhalation. Several of the bodies had bullet wounds as well.

Mubarak, who has said his troops fired a total of only seven bullets, has insisted that the deaths were caused by hand grenades thrown by the hijackers when the assault began. Others have raised the possibility that smoke from a fire ignited by the Egyptians' explosion at the beginning of the operation or from smoke bombs used in an attempt to blind the hijackers were to blame.

Abdullah Fouad Hafez, press counselor at the Egyptian Embassy in Washington, said critics were "jumping to conclusions."

"If the bomb was so powerful and created such a big fire, how did our people enter the airplane?" he asked.

"Can you believe that people going to an airplane to rescue people would throw grenades? It defies logic . . . . Why should we immediately jump to conclusions that it was Egyptian grenades and not hijackers' grenades? We went into this to save lives. That was the main objective of our troops. They did it according to technical training. The bomb used was exactly the one required," Hafez said.

"We are as much interested in knowing the facts as you are. Because most of these are Egyptian people, and we care about what happened. The operation went very smoothly until the fire got out of control. We have to remember that the real culprits in all this are the hijackers."

The Greek government has protested to Egypt and Malta that the operation was carried out without consulting Athens.

"The whole operation was planned and carried out by ignorant amateurs," said Kostas Tzimas, secretary general of the Ministry of Interior and Public Order. "These so-called commandos did not put their lives in any danger at all. They started firing from a distance. Boy scouts could have done a better job than they did. They stormed the plane without knowing what the hijackers looked like or where they were sitting. They just started firing indiscriminately."

U.S. and Israeli officials, on the other hand, have expressed support for the operation.

Referring to the high casualty rate, Israeli Foreign Minister Yitzhak Shamir said, "It's the responsibility of the terrorists, the hijackers. It's not the fault of the Egyptians to try to save the lives of passengers. There is no other way to handle such cases."

The role of the United States in the rescue operation is unclear, although a source in Valletta close to the operation said at least two senior U.S. military officers arrived on the C130 transport with the commandos and provided "technical assistance" for the assault.

"We can't say anything further than that we made an offer of assistance," State Department spokesman Charles E. Redman said. "We're just not going to comment on any specific stories" or the "operational aspects" of the Egyptian rescue effort, he said, insisting that the operation was "very much an Egyptian operation."

A senior State Department official said, "My understanding is that we had some people there. They were there to offer technical advice, but the Egyptians coordinated the operation. I don't see the Egyptians taking advice from us on coordinating it."

Maltese officials have said that one consideration in allowing the Egyptians to carry out the rescue attempt was that they had been warned that the United States would intercept the plane if it were allowed to fly out of Malta.

A week after the hijacking ended, the identity of the hijackers remains enigmatic.

The lone surviving hijacker, believed to be the leader, has been identified only as the holder of a Tunisian passport issued to Omar Marzouki, 20. The other two traveled with Moroccan passports, apparently fake, under the names of S. Bou and S. Chakore, according to Maltese investigators.

The survivor is the man whom pilot Galal says he hit with a fire ax when the Egyptian assault began. He was further wounded by bullets in his chest and remains in the intensive care ward at Valletta's St. Luke's Hospital, apparently out of danger, but talking very little, claiming only that he is Tunisian.

The Maltese government, after initially revealing that one of the hijackers had survived, has since refused to make any further comments about him, citing the need to maintain the wounded hijacker's security and the judicial secrecy of the official inquiry into the hijacking being conducted by magistrate Noel Cuschieri.

The hijackers originally described themselves to Galal as members of the "Egyptian Revolutionaries Organization" or "Egypt's Revolution," a nebulous group whose only previous known activity was the assassination of an Israeli diplomat in Cairo last summer.

Galal and other Egyptair crew members, however, said that the hijackers did not speak with Egyptian accents and sounded more like Palestinians, Lebanese or possibly even Syrians. Diplomats and officials in Malta speculated that they belonged to a dissident Palestinian group opposed to Yasser Arafat's Palestine Liberation Organization, possibly, as Mubarak has alleged, tied to Palestinian renegade Sabri Banna, known as Abu Nidal, an old foe of Arafat.

This, however, does not square with the hijackers' release of Egyptian and Filipino women while refusing to free any of the Palestinian passengers, including three women -- two of them pregnant -- and eight children. Even Egyptian officials in Valletta said they found it hard to believe that Palestinians, whether they were supporters of Arafat or Abu Nidal, would treat Palestinian women and children so inhumanely while showing mercy to women of other nationalities.

"We are sure they are not Palestinians because if they were, I don't think they would have let the Palestinian women and children stay in the plane to die while letting other women go," said Murad Essa Bahlul, the head of the PLO mission in Malta, adding that he had no idea who the hijackers really were.

Certainly they weren't interested in any dialogue with the PLO. Bahlul, like many diplomatic mission heads in Valletta, was in a room below the control tower during part of the time the Egyptian airliner sat on an isolated landing apron in Valletta while its hijackers asked for the plane to be refueled.

When the hijackers asked to talk to representatives of either Algeria or Libya over the aircraft radio, Prime Minister Mifsud Bonnici said that the Libyan representative would talk to them but because there was no Algerian mission in Malta the hijackers might be interested in talking to the PLO representatives.

The hijacker, according to Bahlul, flatly rejected talking to him, saying "he didn't want to speak to an organization that had an office in Cairo, which in turn had made peace with Israel."

The hijacker in the cockpit of the plane did agree to speak to the secretary of the Libyan People's Bureau in Malta, Ali Nagem. But when Nagem got on the radio from the control tower, the hijackers said they would only talk to him in person at the plane. After telephoning his Foreign Ministry in Tripoli, diplomats at the control tower said, Nagem told the hijackers he would not visit the plane and left the control tower. There the contact ended.

The apparent coolness with which the Libyans treated the hijackers does not seem to substantiate Egyptian and American claims that Libya was somehow behind the hijacking. Western diplomats here insist that there is simply no evidence of such involvement beyond the general suspicion that it is the sort of operation the Libyans might have supported.

A second mystery about the hijackers is that they apparently never made political demands. They issued no political statements, asked for no exchange of prisoners and made none of the demands hijackers in the past have typically made. The Egyptair hijackers, according to Galal and Maltese officials, never said why they were hijacking the plane or even what their ultimate mission or destination was.

"All they ever asked was for the plane to be refueled so it could take off again, or food to be brought, and once for the toilets to be cleaned," Galal recalled.

Western diplomats expressed concern that the pattern of hijacking is changing toward a more nihilistic approach of almost ritual killings to make an unclear political point or, as in this case, no discernable point at all.

"These aren't your normal hijackers," said the senior western diplomat in Valletta. "These were a new breed who killed willingly and with no remorse."

Equally baffling is how the hijackers managed to smuggle their weapons aboard the aircraft.

The hijackers made their reservations in Athens two days before the flight, and ticket coupons suggest that two of them came from Belgrade.

If the arms were put aboard in Athens, as opposed to Cairo, where the flight originated and Greek officials insist it must have happened, it might have been done on the runway. It is unlikely that the hijackers would have risked walking the weapons through a series of X-ray checks and hand luggage inspections.

Rodney Wallis, head of security for the International Air Transport Association, said Friday that there was inadequate security around parked planes at the Athens airport, The Associated Press reported.

"The investigation is centering on the ramp area, which is vulnerable. There have been instances where a man disguised as a member of the ground crew managed to reach the ramp of a plane undetected," Wallis said.

Abdel Hamid Bakoush, former Libyan prime minister exiled in Egypt and the target of an assassination attempt a year ago, said the arms used in the hijacking probably were given to the hijackers after they passed security checks by employes of the Libyan airline.

Mubarak has pointed to Libyan leader Muammar Qaddafi as the prime suspect in the hijacking, but his accusation has to be judged in light of Mubarak's domestic needs.

"There is always an added advantage in pointing the finger at Libya -- it shores up the government's internal position," said one Western European diplomat in Cairo. "If they can get these deaths, in the people's minds, on Libya, all the better."

However, in this crisis as in the Achille Lauro affair, Mubarak's credibility has been called into question. His specific comments on the case have proved wrong -- as in his statement that he knew that a ringleader of the hijacking was staying in Room 401 of the Grand Hotel in Tripoli, which turned out to be the room of a Senegalese jurist. His assertion that only seven shots were fired by his commandos during the rescue operation has been contradicted by survivors' accounts and has drawn scorn from Greek officials.

Mubarak has said that the objective of the terrorists was to impede the Middle East peace process. If the hijacking was aimed at Egypt, the purpose might have been to destabilize and discredit it as the leading moderate Arab country in the region.

In this analysis, the timing of the hijacking -- shortly after Mubarak and PLO leader Yasser Arafat publicly embraced each other in Cairo -- appears to be an answer by the radicals to the meeting and to the subsequent statement by Arafat on Nov. 7 renouncing terrorism.

"Why should Libya do such a thing right now?" asked one prominent Egyptian analyst. Answering herself, she said, "It's against the Cairo Declaration. It's a way of telling the PLO, 'You are condemning terrorism, but we are acting as such, and you can't stop us.' "

Mubarak has put his troops on the border with Libya on alert, and Libya has accused Egypt of planning an invasion.

Qaddafi, who has denied any role in the hijacking, nevertheless makes no secret of his disdain for the Mubarak government. Qaddafi, asked Wednesday by Robert MacNeil on U.S. public television about Egyptian accusations that he had a hand in the hijacking, said, "We have to support the Egyptian people and incite these people to make revolution and to form the Arab unity, and Arabs must ascend in one rank against their enemies."