The US government delivered a mild but rare rebuke to Israel yesterday when the state department said ith might have misused American-made cluster bombs in its offensive against Lebanon last summer.

Jan. 3-0, 2007- A state department spokesman, Sean McCormack, said that after a US investigation, a preliminary classified report had been sent to Congress so that it could decide whether to pursue the issue. "There were likely violations," he said.

The UN said last year that Israel had dropped 100,000 cluster bombs that remained unexploded, 90% of them in the last few days of the war, calling it "immoral".

The UN mine office said last week it had found hundreds of bomblets of types made by the US among unexploded ordnance recovered in nearly 250 locations in southern Lebanon.

Given the close relationship between Israel and the US, with Washington providing huge financial aid, it is unusual for the US to criticise the country.

When Israel buys cluster bombs and other lethal equipment from the US, it must agree in writing to restrictions on their use.

Mr McCormack said the report "is not a final judgment". He declined to speculate on what action might be taken against Israel if a violation was confirmed.

The Reagan administration imposed a six-year ban on cluster weapon sales to Israel in 1982, after a congressional investigation found misuse of the weapons during Israel's war that year with Lebnon.

There is no international ban on using cluster bombs against fighters. But the Red Cross called for a ban because their indiscriminate nature means civilians are often the victims. The US, Russia and the UK have resisted a complete ban.

Mr McCormack said Israeli officials had been cooperative. The Israeli army has said all the weapons it uses "are legal under international law and their use conforms with international standards".

An Israeli government spokesman, Mark Regev, said he was not aware of the state department report but when the US had raised cluster bombs in the past, Israel had been "forthcoming, detailed and transparent".