A U.N.-brokered cease-fire between Hezbollah and Israel will begin at 8 a.m. (1 a.m. ET) Monday, U.N. Secretary-General Kofi Annan said Saturday in a taped statement. Israeli Prime Minister Ehud Olmert and Lebanese Prime Minister Fouad Siniora agreed on the time, Annan said. But on the conflict's deadliest day yet for Israeli soldiers, he urged both sides to stop fighting immediately. "Preferably, the fighting should stop now to respect the spirit and intent of the council decision, the object of which was to save civilian lives, to spare the pain and suffering that the civilians on both sides are living through," Annan said. But Saturday night, five Israeli soldiers died after Hezbollah fighters shot down their helicopter in southern Lebanon, Israel Defense Forces said. Earlier in the day, 19 Israeli soldiers were killed, seven of them during a battle in southern Lebanon, military officials said. Early Sunday, at least three Lebanese civilians were killed and eight wounded in an Israeli air strike on the southern Lebanese town of Ali al-Nahri in the Bekaa Valley, Lebanese hospital sources were quoted as saying by CNN. On the Lebanese-Syrian border, two Lebanese soldiers were wounded when an Israeli air strike hit their jeep, Lebanese army sources said. In the southern port city of Tyre, Israeli air strikes sent columns of smoke into the air. Arabic-language news networks reported civilians were killed in the strikes. Hours earlier, Hezbollah leader Hassan Nasrallah said that his group would honor the call for a cease-fire once a deal on the timing was reached. The Lebanese government, which includes two members of Hezbollah, unanimously approved Security Council Resolution 1701 on Saturday, Siniora said. The announcement followed a meeting of the Lebanese Cabinet, and Siniora said the Cabinet would meet again Sunday to discuss implementation.