stop heavy fighting still raging in southern Lebanon.

Airstrikes killed at least 19 people in Lebanon, including 15 in one village, and Hezbollah rockets wounded at least five people in Israel. Long columns of Israeli tanks, soldiers and armored personnel carriers streamed over the border.

More than 50 helicopters ferried Israeli commandos into southern Lebanon in what was called the biggest such operation in Israel's history. It was part of an all-put push to drive Hezbollah fighters behind the Litani River, about 18 miles from the border, before the truce.

But Hezbollah fought back hard. Israel said dozen of its soldiers were wounded in the expanded offensive, which has tripled the Israeli troop strength in southern Lebanon.

The Islamic militant group said its fighters killed seven Israeli soldiers and destroyed 21 tanks. Israel said its troops had killed 40 Hezbollah guerrillas over the previous 24 hours.

A senior Israeli official, meanwhile, said Israel expects a Mideast cease-fire to take effect either late Sunday or Monday, depending on an Israeli Cabinet decision Sunday morning and consultations with the U.N. and input from the Lebanese government. The official spoke on condition of anonymity because he was not authorized to discuss the sensitive matter with reporters.

Israeli media reported that the truce would go into effect at 7 a.m. (1 a.m. EDT) Monday but gave no source for the information.

The official's comments contradicted an earlier statement by Israeli army chief, Lt. Gen. Dan Halutz, that Israel expected to fight for another week despite the cease-fire deal. He said Israeli forces _ apparently about 30,000 soldiers now _ would stay in Lebanon until an international force arrived.

Hezbollah's leader, Sheik Hassan Nasrallah, said his militia would abide by the cease-fire blueprint, but said the guerrillas would keep battling Israeli troops while they remained in Lebanon, calling that "our natural right."

His address was televised as Lebanon's Cabinet met to vote on the U.N. plan. Lebanese Prime Minister Fuad Saniora signaled the Cabinet would accept, saying it serves the interests of his country and "shows that the whole world stood by Lebanon."

The Israeli Cabinet was expected to approve the cease-fire Sunday, but Israel appeared ready to keep up its full-scale military campaign until the U.N. plan worked its way through the region's political leadership over the weekend.

The resolution approved Friday night by the U.N. Security Council would create a peacekeeping force by combining a beefed-up version of ineffective U.N. units already in the war zone and 15,000 soldiers from the Lebanese army. The force, which could number around 30,000, would stand between Israel and Hezbollah's militia.

France, New Zealand, Italy and Ireland said Saturday they were ready to provide troops and Turkey said it was inclined to do so.

President Bush issued a statement urging the world's leaders to implement the U.N. plan and help bring real peace to the Middle East.

"The loss of innocent life in both Lebanon and Israel has been a great tragedy," Bush said. "Hezbollah and its Iranian and Syrian sponsors have brought an unwanted war to the people of Lebanon and Israel, and millions have suffered as a result. I now urge the international community to turn words into action and make every effort to bring lasting peace to the region."

Israel has demanded an airtight buffer zone and wonders if U.N. and Lebanese forces are up for the task. A small U.N. military presence _ now about 2,000 observers _ has been in Hezbollah-controlled southern Lebanon since 1978 and has been overwhelmed by the Islamic militant group's rising power, aided by Iran and Syria.

Secretary of State Condoleezza Rice specifically cited Hezbollah's two sponsors in a statement Friday for all parties to "respect the sovereignty of the Lebanese government and the will of the international community."

But the resolution, approved 15-0 in the U.N. Security Council, did nothing to immediately halt the fighting that erupted exactly a month ago and has claimed nearly 900 lives _ including at least 761 in Lebanon and 123 Israelis.

Israeli missiles slammed into the southern Lebanon village of Rachaf, about 10 miles from the Israeli border, killing at least 15 civilians, security officials said. Israeli ground forces also fanned out across southern Lebanon hunting for Hezbollah rocket batteries that have fired unending salvos across the border.

Three people also were killed in strikes on Kharayeb, and a Lebanese soldier was killed in an air raid near an army base in the Bekaa Valley, officials said.

In Sidon, a coastal city between Beirut and the Israeli border, Israeli bombs destroyed a power plant. Farther south, another power facility was hit near Tyre, knocking out electricity to the port, police said.

On Lebanon's northern frontier, Israeli airstrikes hit the highway leading to the Arida border crossing about a mile from the Mediterranean coast. It was the last official border post open for humanitarian convoys and civilians fleeing the country. The highway was impassable, but drivers tried to maneuver through ruts and ditches.

The only other exits from Lebanon are rugged pathways and back roads through deserts or mountains.

Israel seeks to block supply routes for Hezbollah and disrupt their mobility and has warned it would target any vehicles on the roads in southern Lebanon and along other main highways.

On Friday, an Israeli aircraft fired on a convoy of more than 600 civilian vehicles and others carrying 350 Lebanese police and soldiers who left the Israeli-occupied town on Marjayoun in southeast Lebanon. Police said three civilians and an army recruit were killed and 28 people were injured. The mayor of Marjayoun, Fuad Hamra, put the death toll at six.

Israel said the U.N. troops asked permission to lead the convoy, but it was denied. Previous groups were given permission and traveled unharmed, the Israeli military said.

Fighting continued in Hezbollah-held areas around Marjayoun, a strategic hub overlooking valleys used as Hezbollah rocket bases.

Israeli commando units and guerrillas engaged in close combat in a valley near El-Ghandourieh, about 10 miles southwest of Marjayoun, according to Lebanese security officials.

Other Israeli ground forces, backed by aircraft and drones, met stiff resistance as they tried to reach the Litani River.

Israel said its troops destroyed several rocket batteries and killed more than 40 Hezbollah fighters in the last 24 hours. The guerrilla group announced four deaths Friday and three Saturday.

After a morning free of Hezbollah rocket strikes in northern Israel, a barrage of 20 missiles at midafternoon injured two people in Amirim and three in Kiryat Shemona. Hezbollah had been averaging nearly 200 hits each day in the monthlong conflict.

The Litani is seen by Israel as a crucial boundary in its attempt to push back Hezbollah. Israel repeatedly has insisted that the proposed peacekeeping force cannot allow Hezbollah weapons south of the river.

But it will be nearly impossible to rid south Lebanon of the Islamic guerrillas, who are now in the Lebanese Cabinet and run clinics and other charities that are considered essential in rebuilding the region. Their ability to withstand the Israeli military assault has also made Hezbollah heroes across the Arab and Islamic worlds.