Allied bombers yesterday attacked thousands of Iraqi troops moving through southern Kuwait. U.S. officials said they were uncertain whether the Iraqi forces were massing for a major ground attack or attempting to reorganize after an unsuccessful offensive into Saudi Arabia earlier this week.

One intelligence official described the Iraqi forces as remnants of two or three divisions of mechanized reserves who had been moved close to the Saudi border to reinforce the four-pronged attack that was repulsed this week. The intense bombing yesterday appeared to disrupt the Iraqi troop movements, causing some units to retreat northward away from the border, another official added.

Marine Harrier jump jets joined a swarm of other attack planes in blasting what one pilot said were an estimated 800 to 1,000 tanks, armored personnel carriers and trucks caught in the open during an apparent effort to resupply Iraqi troops in Kuwait.

"It's almost like you flipped on the light in the kitchen late at night and the cockroaches start scurrying, and we're killing them," Harrier squadron commander Lt. Col. Dick "Snake" White, 39, of Fort Smith, Ark., told pool reporters. "They're moving in columns, they're moving in small groups and convoys. It's exactly what we've been looking for."

Pentagon officials said last night that an Air Force AC-130 gunship was apparently shot down over Kuwait during an attack sortie. The plane, armed with cannons and machine guns, was carrying at least 14 people and emitted a distress call, according to Pentagon and congressional sources. The loss, if confirmed, would nearly double the number of Americans shot down in the 15-day-old air war.

Pentagon spokesman Pete Williams declined to comment on the unconfirmed accounts and announced a new policy of withholding information about downed allied aircraft until search-and-rescue efforts have been exhausted. Military search teams also combed the desert near of the coastal Saudi town al-Mishab, 20 miles south of Khafji, for two soldiers, a man and a woman, who are missing.

Lt. Gen. Thomas Kelly, senior operations officer for the Joint Chiefs of Staff, told reporters yesterday that officials in Saudi Arabia are investigating whether 11 Marines killed in ground action earlier this week died as a result of "friendly fire" from allied forces. The Marines apparently died when two light infantry vehicles were destroyed. "Is there a possibility it was friendly fire? There's always a possibility. Don't think it was," Kelly said.

The intensive air strikes against southern Kuwait yesterday came as allied forces finished repelling four battalion-size strikes into northeast Saudi Arabia, including one incursion that briefly occupied the vacant town of Khafji.

The Iraqi probes, the first substantial ground action in the Persian Gulf War, continued to puzzle U.S. intelligence analysts, who speculated that Iraqi President Saddam Hussein could be trying to lure the allies into a major ground war or at least entice them to counterattack and come within range of Iraqi chemical artillery batteries.

The four attacks -- each composed of a battalion-size force of roughly 500 men -- appeared to be part of a "reconnaissance in force" mission to gauge allied defenses, Kelly said. Other Pentagon officials speculated that this vanguard was intended to open the way for a larger attack that was at least temporarily stymied by air attacks and the successful blunting of the reconnaissance units.

The four battalions lost at least 42 tanks and 35 other vehicles, Kelly said, rendering them "combat ineffective." Whatever Saddam's intent, U.S. commanders were unanimous in hoping for further attacks, which would pull the Iraqis from fortified defensive positions into the killing zone of allied air, artillery and infantry power. U.S. officials also said the Iraqi attacks would not disrupt the allied air campaign, expected to last at least another two weeks.

"If they mounted an effective thrust to the south, what they would do would be to come out of their fortifications, where we have difficulty rooting them out," Kelly told reporters. "They would be coming into harm's way in a major way, and I think that they would be quite sorry they did that."

Future Iraqi attacks must be channeled through gaps in Iraqi minefields, officials said. "He can only come through in a very narrow band, and if he does, no one here is going to be very upset about that. If he wants to present himself for another disaster, that's fine with us," one Pentagon officer said last night.

Although Gen. H. Norman Schwarzkopf, commander of Operation Desert Storm, described the attempted Iraqi thrust into Saudi Arabia as "significant as a mosquito on an elephant," the Iraqi newspaper al-Thawra called it "the beginning and omen of the thundering storm that will blow on the Arabian desert." Baghdad's Mother of Battles radio urged Iraqi soldiers to advance and pound "the den of filth and corruption and throw the heads of treachery . . . into the dustbins of history."

Iraq fired another Scud at Israel last night, but the missile fell short, in the Israeli-occupied West Bank, without causing any reported injuries or damage. The attack, shortly after 6 p.m. (11 a.m. EST), was the eighth on Israel from western Iraq since the Scud launchings began Jan. 18, the day after the war started. Reporters in Tel Aviv said they heard no firings last night of U.S.-supplied Patriot interceptors, which have been launched only when the Scuds appear headed for population centers.

"The launching tonight strengthens what we already know, that the missile potential continues," said Brig. Gen. Nachman Shai, chief spokesman of the Israeli army. "The problem is not what it was several days ago, but they are still able to fire one or two missiles."

Schwarzkopf said yesterday that Iraq's ability to fire the missiles has been "significantly impaired" by the 1,500 allied bombing sorties dispatched in the past two weeks as part of what Pentagon officials call the "Great Scud Hunt."

In Israel, the national army command also reported that Arab guerrillas in southern Lebanon fired dozens of Katyusha and Grad rockets at Israel's northern border last night, the third rocket barrage in the region in three days. The rockets, which have all fallen short of the Israeli border, are believed to be the work of Palestinian guerrilla groups sympathetic to Iraq, officials in Tel Aviv said.

Some of the 2,600 allied sorties flown yesterday concentrated on attacking a 15-mile-long traffic jam stemming from a demolished bridge on the Baghdad-to-Basra road. One pilot participating in the attack reported that "there were too many burning vehicles to count," according to Brig. Gen. Pat Stevens IV in Riyadh.

A senior Pentagon official said the B-52 bombers pounding Iraqi troops along the Iraq-Kuwait border included some flying out of an airfield in Spain. He declined to identify the field but Spanish Radio said it was at Moron de la Frontera in the southern province of Seville.

The official said the bombers were moved to the Spanish base shortly before the first U.S. attacks Jan. 17 and have been flying missions from there since.

"It's obviously a very sensitive subject" because the Spanish government, after prolonged negotiations, recently obtained a U.S. commitment to reduce its forces in that country, the official said, including the transfer of 72 U.S. F-16 jets to bases in Italy by May.

The Iraqi air force remained virtually immobile yesterday, Kelly said, with only eight sorties flown from two airfields. None of those planes "that we know of went to Iran," he added. Pentagon officials said 98 Iraqi aircraft -- three-quarters of them sophisticated fighters -- have been confirmed as seeking sanctuary in Iran, but an intelligence official said the number may have climbed to more than 120.

British forces yesterday took credit for demolishing a 300-foot Iraqi landing craft in the northern gulf. A Lynx helicopter from HMS Gloucester attacked the craft, which typically has a crew of 47 and can carry 180 soldiers, and left it "dead in the water" east of Bubiyan Island, according to reports in London.

Pentagon officials refused to comment on a statement to Parliament by British Defense Secretary Tom King that he had agreed to an American request to base B-52 bombers in western England. A limited number of B-52s will be temporarily based at the Royal Air Force base at Fairford to "undertake missions with conventional munitions against Iraqi military or strategic targets." King said several other countries also have agreed to station bombers at their bases, but he refused to name them.

At least two dozen B-52s flying from Jiddah in Saudi Arabia and Diego Garcia in the Indian Ocean have dropped thousands of tons of bombs on Republican Guard units in southern Iraq and northern Kuwait over the past two weeks in an effort to decimate Saddam's strategic reserve. More than 360 attack sorties were flown against the Guard yesterday, including some by the long-range bombers, and the strikes are expected to intensify, U.S. official said.

In a series of network television interviews yesterday, Schwarzkopf belittled much of the Iraqi military and accused Saddam of being "a mass murderer" and a "terrorist."

"I guess I would say I have great disdain for the man," Schwarzkopf said. "I certainly have no respect for his moral or ethical principles. I have no respect for him as a military leader. . . . He's not a military leader by any stretch of the imagination. All he is is a terrorist."

Schwarzkopf also said, "I fully expect him to use chemical weapons" before the war ends. "He has used every other . . . weapon of terror, and I don't see any reason why he's not going to use that."

Schwarzkopf said that the Iraqi leader appears either not to know the extent of success of the allied campaign against him or is deliberately distorting the results.

"Let's face it," he said, "what have they done to date? The air force has done nothing. The navy has . . . done absolutely nothing. . . . The air force has abandoned the army on the ground and run away to a neutral country. They have fired a few Scud missiles, most of which have been intercepted. . . . And now there's one small probing attack {with} very heavy losses. That's not exactly a distinguished set of accomplishments to date."

He also said there were reports that the Iraqi navy had begun to seek shelter in Iranian waters, much as Iraqi air force planes have been taking refuge in Iran.

Calling war a "very emotional thing," Schwarzkopf said the first U.S. casualties attributed to the ground war might have an unsettling effect on the American public. "War is going to kill people," he said, "and . . . if this is sobering to the American people, I don't think that's unhealthy. As a matter of fact, I think it's important that the American people understand that." But he said anyone involved in ground warfare learns quickly not to let casualties deter him. "You regret the loss of life, but you also learn very quickly to put that behind you, because if you dwell on that . . . you are in a lot more danger yourself."

Commenting on the deaths of the 11 Marines, some Democratic lawmakers suggested that the public is not prepared for the carnage that could result from full-scale ground fighting.

"I think we have expectations that are unrealistic," said. Rep. Les Aspin (D-Wis.), chairman of the House Armed Services Committee. The war to date has been "essentially devoid of casualties," Aspin added, creating "a standard impossible to match."

International teams trying, meanwhile, to fight the giant oil spill from Kuwait's main loading terminal have postponed efforts to preserve Persian Gulf wildlife and instead focused on vital desalination and electrical plants, officials said yesterday. Those facilities provide two-thirds of the drinking water and much of the power to the 18 million people living in the area.

Cleanup crews, hampered by a shortage of oil booms and other cleanup equipment, may have to leave some gulf desalting plants unprotected, according to U.S. Coast Guard Lt. Commander Paul Milligan, who is helping Saudi Arabia fight the 11-million barrel spill blamed by U.S. officials on Iraqi sabotage. Serious water shortages are unlikely, officials added, because the peninsula has more than three dozen such plants, including some on the Red Sea coast.

A second, much smaller slick -- also blamed on the Iraqis -- has been spotted in the northern gulf near Mina al-Baqr. Schwarzkopf said Wednesday that U.S. bombers would attack facilities there if necessary to halt the oil leakage, but there was no report of such action yesterday.

A spokesman for a Kurdish opposition group said about 129,000 deserters from the Iraqi army and 150,000 civilians have sought refuge in northeast Iraq. The spokesman, Ahmed Barmani, also said an allied pilot captured after his plane was shot down over Mosul near the Turkish border was subsequently killed by the Iraqi secret police, who tied his body to a car and dragged it through the streets. Other Kurdish opposition sources in Europe said the pilot was an American and was stabbed to death after ejecting from his plane. The reports could not be confirmed.

There were antiwar protests yesterday in South Korea and Algeria, with reports of terrorist attacks linked to the gulf crisis in several other nations.

The biggest antiwar demonstration came in Seoul, where about 200 students, objecting to increased South Korean assistance to the war effort, clashed with police. There were no arrests or reports of injuries. In Algeria, thousands of Moslem fundamentalists burned flags in opposition to the allied war effort. Meanwhile, terrorists in Jordan, Yemen and the Philippines attacked targets belonging to members of the allied coalition, including the U.S. Embassy in Yemen, which was hit by gunfire, and the French Cultural Center in Jordan, where a small fire was set by a group that broke into the building overnight.

State Department spokesman Margaret Tutwiler said yesterday there have been about 70 reported incidents of terrorism worldwide since the gulf war began. But she added that the relationship between the groups suspected of being responsible and the Iraqi government is not clear.

In the United States, a top FBI official said tightened security is likely to last well after the war ends. "I tell our agents it's a mile or two-mile race and we are only in the first lap," William M. Baker, FBI assistant director, told reporters. Baker also said the FBI is investigating 13 reported incidents of harassment against Arab Americans that have occurred since the outbreak of the war.

The commander of the Italian naval forces in the gulf resigned this week over a controversial magazine interview in which he appeared to question the war. Adm. Mario Buracchia, who commanded five Italian warships in the region, quit after leading members of Italy's coalition government demanded his ouster. A weekly news magazine had quoted the 50-year-old commander as suggesting that armed conflict could have been avoided, and speculating that the allies had underestimated the implications of the war.

Buracchia initially denied the comments but journalist Guglielmo Sassini, who had spent five days aboard the Italian battleship "Audace," produced a recording of the interview.

Staff writers Barton Gellman, R. Jeffrey Smith, Tom Kenworthy, Helen Dewar, George C. Wilson, correspondents Glenn Frankel in London, William Claiborne in Jerusalem and staff researcher Lucy Shackelford contributed to this report.