Israel, in its military operations in Lebanon, has violated U.S. restrictions on use of American-made weapons, several influential members of Congress and foreign policy analysts said yesterday. But there was disagreement on what steps the United States should take in response.

Several lawmakers, including House Foreign Affairs Committee Chairman Clement J. Zablocki (D-Wis.), said they believed Israel had violated the Arms Export Control Act, which stipulates that U.S. military equipment may be used "solely for internal security and for legitimate self-defense." Sen. Paul E. Tsongas (D-Mass.) and several House members also said the Israelis had violated specific bilateral agreements between the two nations over the use of cluster bombs.

President Reagan's former national security adviser Richard V. Allen and former undersecretary of state George Ball, testifying before the Senate Foreign Relations Committee yesterday morning, also agreed that violations had occurred. But Allen defended Israeli actions, citing "extenuating circumstances."

Congressmen from both political parties expressed anger that the Reagan administration has delayed for nearly six weeks a report to Congress on whether Israel has violated the arms export law. The act requires such a report but sets no deadline. There also was anger that Israel has not responded for nearly a month to U.S. requests for information about the use of American-made cluster bombs in Lebanon.

"It has taken this administration longer than any administration in past history to comply with the law," said Senate Foreign Relations Committee Chairman Charles H. Percy (R-Ill.).

Percy said he has warned Israel's U.S. ambassador, Moshe Arens, that any use of American weapons in assaulting besieged West Beirut would trigger a serious move in Congress to suspend military aid to the Israelis.

The law does not require that military aid be suspended even if the Israelis are found to have violated the act. Zablocki, interviewed after his committee held a closed-door session with two State Department officials to discuss Israeli weapons use, said that despite his belief the law had been violated, "I would be surprised if Congress takes action." Alluding to popular support for Israel in the United States, he added, "It's an election year."

Wat T. Cluverius, deputy assistant secretary of state for near eastern affairs, told Zablocki's committee publicly that the administration was not considering any delay in arms shipments to Israel while it was determining whether the Israelis violated the law. Cluverius said the determination would be completed within the next few days.

Rep. Mary Rose Oakar (D-Ohio), who has called for U.S. sanctions against arms shipments to Israel because of its Lebanon invasion, said after the session, "You would have to be deaf, dumb and blind to ignore the fact that Israel has violated the law."

Israeli officials have contended the invasion was a legitimate self-defense measure because of Palestinian shelling of northern Israel and the continuing threat of armed Palestine Liberation Organization guerrillas in Lebanon. They have acknowledged the use of cluster bombs but contended the weapons have been used selectively against concentrated military targets.

Since 1976, U.S. officials have acknowleged privately, classified agreements signed by U.S. and Israeli officials have stipulated that cluster bombs may only be used against the armed forces of legitimate nations under "special wartime conditions" in which Israel is in combat against two or more states.