The United Nations Mine Action Coordination Centre has said unexploded Israeli cluster bombs have been found in 285 locations in south Lebanon.
Dalya Farran, a spokeswoman for the Coordination Centre, said UN teams were finding about 30 news locations with unexploded bombs a day.
Cluster bombs have killed at least eight people and wounded 25 since the truce.
A report in today's edition of the New York Timesquoted several current and former US officials as saying they doubted a US State Department investigation into Israel's use of US-supplied munitions would lead to sanctions against Israel,
They said it might be an effort by the Bush administration to ease Arab criticism of its military support for Israel.
UN demining experts refused to comment on the US investigation, but suggested Israel had violated some aspects of international law.
"It's not illegal to use (cluster bombs) against soldiers or your enemy, but according to Geneva Conventions it's illegal to use them in civilian areas," Ms Farran said. "But it's not up to us to decide if it's illegal - I'm just giving facts and letting others do analysis."
The south of Lebanon is also riddled with land mines, laid by Israeli soldiers as they pulled out of the region in 2000, after an 18-year occupation.
Hizbullah has also planted mines to ward off Israeli forces. Lebanon has long called for Israel to hand over maps of the minefields.
AP