By Hussein Saad

TYRE, Lebanon, Aug 12 (Reuters) Israeli forces made their deepest thrust yet into southern Lebanon today, pushing towards the Litani River as they began an expanded ground offensive against Hizbollah guerrillas.

An Israeli force reached the village of Ghandouriyeh, some 11 km (7 miles) inside Lebanon, security sources said, the deepest Israel has advanced in a month-old war that has seen it strike Lebanon by air and land.

Hizbollah, acknowledging the advance, said its guerrillas ambushed the force in Ghandouriyeh, east of the port city of Tyre, killing and wounding a number of Israeli soldiers.

Further north in Kharayeb, an Israeli air strike targeting a pick-up truck killed at least four civilians, medical sources said. Several people were killed and more wounded in an earlier air strike on the village of Rshaf, security sources said.

The Israeli army said today that it had started broadening its ground offensive in south Lebanon on the orders of Prime Minister Ehud Olmert and Defence Minister Amir Peretz after the U N Security Council adopted a resolution calling for an end to the fighting.

Israeli officials said before Friday's U N vote that the army would press on with its military campaign against Hizbollah at least until Olmert's cabinet met tomorrow.

Israel gave no immediate word on the level of resistance its forces were facing as they moved towards the Litani, which lies only a few kilometres from the Israeli border at some points but some 20 km (13 miles) away at others.

About 10,000 Israeli troops had been carving out a ''buffer'' zone in the area and Hizbollah said its fighters destroyed an Israeli tank and bulldozer east of the village of Tiri, wounding or killing several Israeli soldiers.

The Shi'ite Muslim guerrilla group said it was also trying to push back an Israeli military bulldozer that was advancing on Aita Shaab. It fired an anti-tank missile at an Israeli armoured force advancing towards the Saf al-Hawa area near the town of Bint Jbeil, destroying a tank.

Witnesses reported heavy shelling in many areas of south Lebanon, including villages north of the Litani River.

Fighting erupted on July 12 after Hizbollah guerrillas abducted two Israeli soldiers in a cross-border raid. Israel launched an air and ground campaign, and Hizbollah started firing rocket barrages into northern Israel.

No Hizbollah rockets landed in Israel today morning.

Israel occupied southern Lebanon for 22 years, withdrawing in 2000 under constant attack by Hizbollah, which now has 14 deputies in Lebanon's parliament and two ministers in the cabinet.

REUTERS AB HT1607