Israeli Army Radio said that Israeli ground forces are entering Lebanon to search for two soldiers who were kidnapped by Hizbullah on Wednesday.

The radio said that large numbers of troops, as well as aircraft, were taking part in searches on the Lebanese side of the border.

Earlier, Israeli defense ministry confirmed the kidnapping of two Israeli soldiers by Hizbullah, and said it held the Lebanese government "directly responsible" for their fate and safe return.

"The Lebanese government is responsible for the fate of the Israeli soldiers, and must take immediate action to locate them without harming them and return them to Israel," the ministry said in a statement. A statement released by Hizbullah said the two soldiers "were moved to a safe place".

In Lebanon, two civilians were killed and a soldier was wounded in an Israeli air raid on a bridge in south Lebanon, Lebanese security sources said.

They said Israeli warplanes bombed three key bridges in the area shortly after Hizbullah guerrillas said they captured two Israeli soldiers in a cross-border attack. The Lebanese casualties occurred in the raid on the coastal Qasmiyeh Bridge.

Earlier, intense cross-border clashes that left at least four Israeli civilians wounded, according to Israeli military sources.

Hizbullah fighters fired dozens of Katyusha rockets and mortar rounds on the disputed Shebaa Farms border area, security sources said.

There was also a barrage of fire on northern Israel at the other end of the frontier close to the Mediterranean coast, the sources added.

The shelling, accompanied by automatic gunfire, began at 9:00 am (0600 GMT), Israeli military sources said.