JERUSALEM - Prime Minister Ehud Olmert ordered Israel's army to observe a ceasefire in Lebanon from 2 a.m. on Monday (2300 GMT Sunday) except in self defense, the Haaretz newspaper's Web site said.

(L-R) Israeli Foreign Minister Tzipi Livni, Deputy Prime Minister and Minister of Transportation Shaul Mofaz, Israeli Prime Minister Ehud Olmert, an unidentified official and Vice Premier Shimon Peres. Israel will negotiate for the release of two soldiers whose capture by Hezbollah militants on July 12 sparked the Israeli offensive in Lebanon, Livni said.[AFP]

It said some troops would be withdrawn from southern Lebanon immediately while others would remain to hand over to an international force.

A U.N.-brokered truce between Israeli forces and Hizbollah guerrillas is formally due to take effect at 0500 GMT.

Haaretz said Olmert had met his defense minister and heads of armed forces late on Sunday to discuss the ceasefire.

"Olmert ordered the army to begin abiding by it as of 2 a.m. this morning, other than in cases of self-defence," the newspaper said.

Neither Olmert's office nor the army had any immediate comment.