Israel violated U.S. restrictions on the use of American-made cluster bombs in its military operations in South Lebanon, the State Department confirmed yesterday, and the United States is seeking to prevent any further breach of the agreement.

Cluster bomb units were one of the most controverial American weapons in the Vietnam war. The CBUs are dropped from aircraft in a canister that opens to scatter small bombs or grenades containing various types of sharp shrapnel across a wide area with devasting effects on people.

American news accounts of the Israeli action against Palestinan guerrilla camps last month reported use of the cluster bombs. Rep. Paul N. McCloskey (R-Calif.), a critic of the American role in the Vietnam War, has charged that Israel employed the cluster bombs against civilians in South Lebanon.

"We have confirmed that Israel used CBUs supplied by the United States," a State Department spokesman said yesterday. "Israel has told us they were used exclusively against military targets - and specifically against artillery targets."

State Department officials said the limited independent information that the United States has obtained does not contradict that Israeli contention. However, at issue are other U.S. restrictions on the weapons, which are understood to limit their use to all-out warefare or specified types of military action.

A spokesman would say only that Israel's has given us assurances that it would observe certain specific restrictions governing the use of CBUs. I cannot go into the details, but Israel's use of CBUs in its recent military operation in South Lebanon was contrary to those restrictions.

"We are having discussions with the Israeli government with a view to assuring that those restrictions will be observed in the future."

Officials also said that the CBUs, like all other American-supplied weapons, are covered by the mutual defense agreement of 1952 between Israel and the United States. Secretary of State Cyrus R. Vance reported to Congress last week that "a violation of the 1952 agreement may have occurred by reason of the Israeli operation in Lebanon." But Vance went on to say that because Israel has said it intends to withdraw its forces from Lebanon, he was not rcommending any further action by President Carter regarding the use of American weapons supplied to Israel for defensive purposes.

In a view of that letter by Vance, a State Department spokesman said yesterday, in commenting on the cluster bomb issue, "we do not believe that any further action with respect to Israel is required under the law, as the secretary stated in his letter."