Three hundred Lebanese prisoners were freed by Israel here today, emerging from months of captivity bewildered and unaware of the hijacking of an American airliner last month in which their continued detention had been a key issue.

The release of the prisoners, most of them Shiite Moslems, left 435 still in detention at Israel's Atlit Prison. Shiite hijackers of the TWA airliner last month had demanded release of all of the prisoners, but Israeli officials insisted today's mass release was not connected to the freeing earlier this week of the remaining 39 Americans taken hostage by the hijackers, Washington Post correspondent Edward Walsh reported from Jerusalem.

Israeli Defense Minister Yitzhak Rabin said the 300 were freed as a "continuation of our policy." He added that "there is no linkage between release of the hostages and our policy."

Amid joyous celebrations by relatives and friends here and in nearby Tyre, Shiite leaders demanded the release of the remaining Israeli prisoners and threatened to continue their attacks against the Jewish state.

"While congratulating the 300 brothers released from Atlit today, our joy will only be whole when the rest come," Nabih Berri, leader of the Shiite Amal movement and a key figure in the release of the TWA hostages, said today.

Amal's militia commander in southern Lebanon, Daoud Daoud, told reporters he would fight the Israelis until all Lebanese prisoners were freed and Israeli troops have left all of Lebanon. "My happiness is incomplete because there are other dear friends still in prison and because part of my land is still under occupation," Daoud said.

The prisoners released today were among hundreds seized by Israeli troops in southern Lebanon in recent months as Israel attempted to protect its withdrawing invasion force from attacks by Lebanese.

Israel has rejected complaints by the United Nations and the United States and other countries that its transfer of the Lebanese prisoners to a detention camp in Israel violated international law.

David Kimche, director general of the Israeli Foreign Ministry, said in Washington Wednesday that the transfer of the prisoners had been a necessity and thus permissible under international law. He said that the arrests had been approved by Israeli judicial officials and that, in all of the more than 700 cases, Israeli authorities had evidence that the suspects had been involved in anti-Israeli attacks or were preparing for them.

Relatives and Shiite militiamen with pink oleanders stuck in their rifles lined roads out of Ras Bayyada, seven miles north of the Israeli border, where the transfer of the prisoners took place today.

Amal officials, with walkie-talkies in one hand and prayer beads in the other, paced impatiently on side roads until an International Red Cross convoy of six buses, three vans and 10 cars crept from around a white cliff jutting out into the Mediterranean.

Waffiyeh Banjak sat on a rock nearby while the transfer of the prisoners was made as their names were read out. She was waiting for her 21-year-old son Hussein, who never showed up.

Village women in scarves and Shiite militiamen wearing bright green bandannas threw rice at the freed prisoners when the convoy rumbled into southern Lebanese towns in the early afternoon. Three men on crutches were taken to a Red Cross ambulance, according to photographers allowed to witness the release at close range.

Several of the freed prisoners charged that they had been tortured, beaten, and otherwise mistreated.

Aly Fayyad, 21, from Zrariye, said that while in prison they had been forced to sit cross-legged on the ground with their hands above their bent heads five times a day for head counts by their guards. "Whoever moved his head ever so slightly was beaten with a stick," he said.

Freed prisoner Mousa Mohammed Mrouweh said in Tyre that "the Israelis tortured us, beat us and humiliated us." Mrouweh, dressed like the other released prisoners in a white-and-blue track suit and plastic slippers, looked relatively healthy but dazed by the tumult around him. He said he had been part of the National South Lebanon Resistance Front, which specialized in hit-and-run attacks against Israeli soldiers, and was arrested in an Israeli raid on Zrariye in March.

"I have told the Israelis during my interrogation that I would not hesitate to attack them if they reentered," he said.

None of the prisoners interviewed had heard of the hijacking, saying they had been completely cut off from the outside world and news during their detention.

Ali Mdeiheli, 12, said he had come to seek his 18-year-old cousin Imad, who had been seized in Tyre by Israeli intelligence officials.

"I came straight from school and I won't go have lunch until I see Imad," he said. "My cousin never carried weapons but he worked with the Lebanese resistance movement. When I grow up I will be like him.

"I cried the day they took him. I was afraid I'd never see him again. He ran away in his pajamas but they still caught him."

Among those rushing to embrace loved ones at the Red Cross rest house in Tyre was Batoul Zorqot, carrying her daughter, Sawsan, 3. She said the Israelis seized her husband, Hussein Ghazi, on Nov. 19, 1984, during a raid on the village of Kharayeb. "When they took him I threw stones at them. We had nothing else to fight with," she said.

"The Israelis shot at me and hit me in the leg. I was seven months pregnant with twin girls, who died in a premature delivery," she added. "I was proud my husband was a resistance fighter, but I am against hijacking -- despite the fact that it has served to release Hussein."

Ghazi described his unexpected release and reunion with his wife and daughter as a "rebirth in heaven." He said he was even more happy to see "so many people relieved to see Israel far from their villages thanks to operations I paricipated in."

Among the welcomers was Hiyam Gharib, 25, from Bazouriye. She said the Israelis had taken her, too, seven months ago when they caught her and her younger sister working on a bomb. "Many girls work in the resistance," she said.

"There was a clash, then the Israelis came to the house and took me to their intelligence center in Rashidiye. They beat me, cursed me and tried to rape me just to intimidate me but they didn't," she charged.

She said she had become a resistance fighter secretly but that when her parents found out they were very supportive.

The villagers of Jibsheet today celebrated the first anniversary of the death of Bilal Fahs, who blew up himself and an Israeli tank. But Gharib said she was not thinking of suicide operations "because I have done a lot being alive, and as long as I am living I will do more."

A young woman watching the prisoner release earlier said she was opposed to hijackings and violence because "blood brings blood and peace brings peace. We don't want our peace through the kidnaping of others and we don't want any one to kill us."

Meanwhile, fighting broke out around the Burj al Barajinah Palestinian refugee camp in southern Beirut -- site of devastating fighting last month between Shiites and Palestinians -- as reconstruction efforts were about to begin under a two-week-old Syrian-brokered truce.