Seven Israeli soldiers were killed during fierce fighting in south Lebanon on Saturday, Israeli local television reported.

The Israeli army confirmed that seven Israel Defense Forces (IDF) troops were killed and some 80 were injured, 11 of them sustaining serious wounds when the army expanded an operation into south Lebanon on the 32nd day of Israel-Hezbollah conflict.

Under cover of intensive artillery fire, IDF troops reached the Litani River, some 30 km inside Lebanon, Israeli newspaper Ha'aretz reported on its website edition late Saturday, citing military officials.

About 50 Israel Air Force helicopters dropped a large number of soldiers deep inside Lebanon, as part of an expanded operation, the report said.

Sources in the IDF described the move as "the biggest operation carried out in recent years".

The large casualties were caused on the same day when Israel announced that a UN-brokered ceasefire would go into effect at 7 a.m. (0400 GMT) Monday morning.

Both Israel and Lebanon were expected by Sunday to endorse the UN resolution calling for a cessation of hostilities.

However, Israel Defense Forces (IDF) Chief of Staff Dan Halutz said on Saturday that the fight with Hezbollah would continue for another week, despite a UN ceasefire resolution.

The IDF has almost tripled its troops in southern Lebanon as part of its expanded ground offensive, Halutz said, adding that IDF troops would stay there until an international force arrives.

On Friday, the UN Security Council unanimously adopted a resolution 1701 that calls for Israel's withdrawal and authorizes an increase of the existing UN force in Lebanon to 15,000 troops to help Lebanese troops take control of south Lebanon as Israel withdraws.

France and the United States, co-sponsored of the draft resolution, came up with a compromise final version after days of hard wrangling. And the resolution has left out some key demands from both Israel and Lebanon in efforts to produce a workable arrangement.

Israel has been fighting Lebanese Hezbollah since the Shiite group kidnapped two Israeli soldiers on July 12.