Fist-shaking Shiite demonstrators marched near the hijacked TWA plane parked at Beirut Airport today chanting "Death to America" and trampling and burning an American flag.

Security guards from the mainstream Shiite Amal movement ringed the aircraft for protection as chador-clad women and bearded young men sat in rows yelling and roaring in unision: "Death to America, the Great Satan."

More than a 1,000 Hezbollah (Party of God) militants swarmed onto the tarmac after the noon Friday prayers. Some of the Hezbollah followers came in buses; others walked more than a half mile in the sweltering heat from a mosque along the airport road to participate in the anti-American spectacle.

Three American crew members of the plane, hijacked by Shiite activists while on a flight from Athens to Rome a week ago, reportedly were aboard, but they could not be seen. Three hijackers wearing dark blue paper bags over their heads appeared to salute the cheering crowds from the top of a mobile airlines staircase. The hijackers and five mullahs worked the mob into a frenzy with cries of "Allahu Akbar God is great ; we are seeking martyrdom."

Complete with a Hezbollah video cameraman, the well-planned demonstration was reminiscent of demonstrations organized by militants outside the U.S. Embassy in Tehran in 1979 and 1980.

Hezbollah is a loose umbrella group for Shiite religious extremists with ties to Iran. Two of its members are reported to have commandeered the TWA airliner to focus world attention on a list of demands that has now been reduced to the release of 766 Shiite Moslem and other Arab prisoners held in the Israel coastal town of Atlit.

[Israeli officials say that only two-thirds, or about 500, of the prisoners at Atlit are Lebanese Shiites].

Shouting "Death to Israel and America, the Great Satan," the throng of young men and women, wearing flowing black robes, Iranian-style trousers and shifts, distributed leaflets in support of the hijackers. "Let us declare support for the plane hijackers. Let us declare solidarity with our imprisoned brethren in Israel's Atlit Prison. Let us condemn America's crimes and global terrorism," one leaflet said.

Forty Americans are being held hostage pending the release of the Lebanese prisoners. Reports that one or two American hostages, Jimmy Dell Palmer of Little Rock, Ark., and Claude Whitmoyer of Severn, Md., would be freed because of ill health could not be confirmed. Amal spokesman Ali Hamdan told journalists that Palmer, 48, was "not sick anymore; he's got his medication from the United States." Asked if there were plans to free others, Hamdan replied: "No."

[In Little Rock, Palmer's son said the State Department had informed the family that his father, who has high blood pressure and a heart ailment, had been examined by doctors at the American University Hospital in Beirut, The Associated Press reported. He said he was found to be in good health and returned to his captors].

The demonstration at the airport stood in contrast to a silent Sunni Moslem protest in the western half of the capital against lawlessness and Shiite dominance. A strike was observed following a call by a small Sunni militia, the Union of Working People's Forces, led by Kamal Shatila. Lebanese Prime Minister Rashid Karami, a Sunni, took part in a sit-in at a Beirut mosque in solidarity with the strike, which was interpreted as hostile to the Shiite Amal militia.

Karami was one of three Lebanese ministers to condemn the hijacking, although he said it was "a reaction to injustices" committed by Israel. Inter-Moslem tension has been building up ever since the main Shiite Amal militia, backed by Druze militiamen, crushed the Sunni Mourabitoun militia in fierce street fighting in April. Since then, friction has developed between Amal and its Druze ally, the Progressive Socialist Party.

A brief clash broke out today between Shiite and Sunni gunmen, as shops closed and were forced to reopen by rival Moslem groups. One person was killed and three wounded in the short battle. Sunni-owned shops that had been shuttered in the morning were painted wth black crosses. The fighting broke out when Sunnis returned to rub off the marks.

An Amal statement said later that its fighters chased away "troublesome elements" who painted the signs on shops and had halted their "blackmailing activities" against shopkeepers.

Concern over the hijacking drama has shifted attention away from internal Lebanese problems and raised fears of an "international impasse" over the stalled hostage-prisoner exchange. The Swiss and Austrian governments have offered their good offices in assisting with logistics for a possible prisoner swap.

The Austrian ambassador to Beirut, Georg Znidaric, said that he had been instructed to contact Amal leader Nabih Berri to convey Vienna's offer. "If we can contribute to a solution, we are ready to do whatever we can in negotiating, serving as go-betweens or providing a place for the transfer of prisoners," the ambassador said. Yesterday Berri received a letter from Swiss Foreign Minister Pierre Aubert.

The deadlock in efforts to resolve the crisis is putting Berri's leadership of the Shiite community to the test. Although he has guaranteed the safety of the hostages, the Amal leader does not have full freedom to decide their fate.

The majority of Lebanese Shiite prisoners already released by Israel are members of Amal rather than of Hezbollah, and any leniency by Berri in releasing the hostages is likely to meet with strong criticism. The Amal movement has been accused of concluding a secret deal with Israel to bar guerrillas from launching raids against it in the south, something Berri's movement and Jerusalem have denied strongly.

Berri's involvement in a month-long war against Palestinians to prevent the resurgence of any guerrilla power has not been supported by Hezbollah or its Iranian backers, who found in Yasser Arafat's PLO its first ally in the revolution against the shah.

Berri and his aides have warned repeatedly that if nothing is done to free the prisoners in Atlit, the hostages would be returned to the original hijackers. Amal took over management of the hijacking last Sunday to avoid more bloodshed after an American passenger was shot and killed early Saturday.

A kidnaped Middle East Airlines executive was freed from his captors by a pro-Syrian militia last week and released several days later, The Associated Press reported, quoting police.

[Sami Rababi, the Lebanese national airline's vice president in charge of public relations, was released overnight by members of the National Syrian Social Party, who freed him from his captors on June 15, police and news reports said. Rababi was abducted on the main highway to the airport in Beirut on Feb. 5.]