Amal militiamen, working quickly before dawn, today reportedly moved the remaining passengers of the hijacked TWA aircraft to West Beirut's predominantly Shiite Moslem suburbs, according to airport officials and other well-informed sources.

For the more than 30 passengers taken off the jet, it would be the first time out of the aircraft since it was hijacked four days ago, adding yet another stage of grim uncertainty.

Later, Lebanon's justice minister and chief of the Shiite Amal militia, Nabih Berri, said at a news conference that hostages aboard the aircraft were moved to a secret hideout to avoid casualties from a feared foreign rescue mission.

Berri, who agreed to negotiate on behalf of the hijackers yesterday on condition that they not harm any of the passengers, said the American and Greek hostages were now being guarded by his mainstream Shiite Moslem militiamen "somewhere in Beirut."

Throughout the night there had been "unusual activity around the airport, with many cars and lights moving about," according to western observers who were watching the airport.

Journalists had been forced from the area by militiamen following widespread rumors of an imminent Israeli military action, but a check at the airport shortly after midnight revealed a number of cars, gray jeeps and vans that had not been there three hours earlier.

These vehicles apparently were used to take the passengers, in groups of seven or eight, to their new location, reportedly in the Hay al Sullom neighborhood.

Amal joined the hijack operation "to prevent further bloodshed" and to make sure that it ran smoothly, according to Berri. Presenting the case of the hijackers' demands for the release of Shiite prisoners from the Atlit jail in Israel, Berri said today: "I am not a go-between. I am a party, and I and the Amal movement have adopted the demands of the hijackers in relation to Atlit. This is definite."

Asked whether the hijackers were from Hezbollah (Party of God), the mysterious and extremist Shiite fringe group associated with numerous acts of violence, Berri commented: "I am not sure if they are part of Hezbollah , but they are in the same way," meaning Shiite extremists. Berri responded emphatically when pressed to say whether the hijackers were members of Amal: "Of course not, of course not." He added that the hostages now were guarded by both Amal and the "kidnapers," meaning the hijackers, and that some Amal militiamen were kept on the plane to guard it.

Berri stressed that he guaranteed the safety of all the passengers but could not say whether they were being kept together. He said he did not know where the hostages were being kept, but "my people know."

"I think they are safe and there is no problem about their safety," Berri said.

Berri told reporters that he wanted the passengers outside the airport because he was "afraid something will happen to them." He repeated several times in English and Arabic that all the remaining TWA passengers were now off the plane.

"I take care of the Americans here like human beings; why the Americans don't take care for the human beings of the Lebanese and others in Atlit prison?" Berri asked, charging that U.S. policy is slanted toward Israel. He claimed that the 700 or so Lebanese prisoners in Atlit had also been "hijacked" by the Israelis, who violated the Geneva convention on how to treat war prisoners by taking them into Israel.

"I gave guarantees to the hijackers that I will not release the hostages or the passengers without the release of the Atlit prisoners. And I gave guarantees to the Americans and to everyone, the Greeks, that no one will get hurt," he said. In a separate interview, Berri warned: "If Israel does not release the Lebanese prisoners I would say to the kidnapers, 'Now you take the people and do what you want.' "

Although Amal officials at the airport said no one had left the plane, other sources there said the evacuation was done while the aircraft's engines were running. For some reason, the engines were still on this evening. The plane had been moved closer to the central tarmac.

Berri's announcement was met with initial suspicion, but Beirut-based western diplomats said they "tended to believe" the evacuation has taken place.

An Amal militiaman, who said he stood guard until 3 a.m. local time, insisted that nothing had happened. Amal information officials expelled journalists and cameramen from the airport complex after midnight. A photographer, who arrived at 5:30 a.m. and kept a vigil of the parked TWA plane through a special lens until this evening also said he saw nothing. The operation to move the passengers most likely would have taken place between 4 and 5:30 a.m.

The sources, who confirmed the transfer from the plane, said the crew members also had left the plane, but this information conflicted with reports from elsewhere that the crew were still aboard.

"I have personally ordered the evacuation . . . because we are afraid of an operation or a battle in which all of them will be killed," Berri said.

There was confusion earlier today stemming from orders for food by the hijackers. For breakfast they initially said they wanted 15 sandwiches. When an official disbelievingly asked whether that would be enough, they requested 100 more.

"There were times when I felt the passengers were with them and others when they gave me the impression they were alone. They were asking about the situation outside," an air controller said. At another point, they ordered 40 chicken lunches and large quantities of water. Local radio stations said the hijackers were leaving the plane to go visit their relatives in the suburbs and at one point received visitors as well.

The airport itself seemed cleaner and better kept than in the past few days. There were relatively few Amal militiamen compared to the first stages of the crisis, when the airport was crowded with gunmen, who appeared to sympathize with the hijackers and admire their bravery.

There are now believed to be 12 hijackers. Initially there were two on board, who are believed to be from the fundamentalist Hezbollah extremist Shiite group. Sources said they were then joined by nine Amal fighters and two other members of Hezbollah. Early Saturday, one of the first hijackers was taken off the plane. Sources said he had shot the American passenger in a rage, when he did not comply with orders to keep his head down.

The U.S. Embassy in Beirut has been in close touch with Berri on and off today, but embassy officials insist that this is "only in his capacity as justice minister and member of the Lebanese government." The U.S. diplomatic mission here also has conferred with Lebanese President Amin Gemayel and his interior minister, Joseph Skaff. Little has been heard from Gemayel throughout the latest hijacking crisis.