Israeli warplanes bombed the outskirts of West Beirut and its southern suburbs for the fifth consecutive day today, hitting a Palestine Liberation Organization ammunition dump as well as Palestinian and Lebanese residential districts.

The air strikes in the afternoon and evening followed artillery and machine-gun exchanges overnight between Israeli and PLO forces. The Palestinian news agency Wafa claimed that the afternoon air raids and shelling from land and sea had left 54 civilians dead or wounded, saying that this brought to 101 the number of civilian casualties during the past 24 hours.

A U.S. congressman called for a cutoff of military assistance to Israel because of its earlier use of U.S.-supplied cluster bombs, an antipersonnel weapon that spews deadly shrapnel over a large area when it explodes. Rep. Paul McCloskey (R-Calif.) told a news conference in predominantly Christian East Beirut that Israel had "deliberately violated" an agreement with the United States requiring that the bombs be used only for defensive purposes.

McCloskey and five other members of Congress arrived yesterday on a fact-finding tour and immediately caused an uproar when McCloskey claimed that PLO Chairman Yasser Arafat had signed a statement implying recognition of Israel. PLO leaders made clear that they would extend such recognition only in return for acceptance by Israel of the Palestinians' right to a state of their own.

McCloskey told reporters today that it was "incumbent on our committee to go back to Congress and recommend a joint resolution cutting off all military assistance" to Israel.

The White House announced a week ago that it had delayed a shipment to Israel of 4,000 cluster-type artillery shells while reviewing whether Israel had violated U.S. arms export laws and other special arrangements in using cluster bombs in Lebanon. Israel has sent a letter to the U.S. government saying that the bombs had not been misused because they were employed only against military targets, Israeli radio has reported.

Another representative, Mary Rose Oakar (D-Ohio) said, "There is no question that our weapons are responsible for this horrific, horrendous destruction." She was referring to scenes of bombing and shelling that members of the group had visited yesterday during a brief trip to mainly Moslem West Beirut, the stronghold of 5,000 to 6,000 Palestinian guerrillas trapped by a ring of Israeli troops and armor.

However, another congressman, Elliot Levitas (D-Ga.), said that he was "not prepared to accept the testimony of PLO terrorists" on the cluster bomb issue and that more information was needed.

In today's press conference, McCloskey described the note Arafat signed yesterday as a step toward recognition of Israel but acknowledged that Arafat had refused to accept specifically U.N. Security Council Resolution 242, which implicitly recognizes Israel.

McCloskey said that the Palestinians "clearly are ready to recognize Israel's right to exist." Levitas contradicted him, however, saying, "In my view, Chairman Arafat's statement was at best a rehash of what had been said before and at worst an attempt at a propaganda maneuver and to gain time as well."

The document signed by Arafat said simply, "Chairman Arafat accepts all United Nations resolutions relevant to the Palestine question." That left open whether the statement included acceptance of Resolution 242, which does not refer to the Palestinian question by name.

The delegation's visit also caused a stir in East Beirut when McCloskey quoted the commander of the Christian Phalangist militia Bashir Gemayel as saying that he did not care what happened to Moslem West Beirut in the current fighting.

Christian and Moslem militias fought a bloody sectarian war in 1975-76. Spokesmen for Gemayel, who has just announced his candidacy for president of Lebanon in a forthcoming election, denied McCloskey's statement. They insisted that Gemayel was deeply concerned about the fate of the Moslem western sector of the city.

Several hours after the delegation's press conference, Israeli fighter-bombers appeared in the sky over West Beirut, drawing the usual ineffectual antiaircraft fire from Palestinian and Lebanese leftist guerrillas.

In addition to bombing Palestinian camps and residential areas south of the city, the planes scored a direct hit on an ammunition depot a few blocks inland from the Mediterranean coastal road. A huge explosion was followed by a series of secondary blasts as munitions blew up and rockets arched into the sky. A cloud of brownish smoke billowed into the air, and a large fire continued to burn for at least two hours.

The Israeli raids are apparently designed to put pressure on the PLO to negotiate a settlement providing for the evacuation of its leaders and guerrillas from Beirut.

Earlier this evening, Israeli troops in East Beirut had cut off electricity to the western sector for the second time since Saturday, drawing sharp protests from Lebanese government officials.

The Palestinian agency Wafa claimed that guerrillas had repulsed an Israeli landing attempt on the coast of West Beirut during the night.

[Israeli military sources in Tel Aviv denied the claim, The Associated Press reported.]