Hamas leader killed amid escalating offensive

Israel assassinated a Hamas strongman today in its first assault on the top leadership of the territory's ruling group, escalating a crushing aerial offensive even as it declared itself ready to launch a ground invasion.

While turning up the heat on the battlefield, Israel appeared to be sounding out a possible diplomatic exit from its campaign, demanding international monitors as a key term of any future truce with Gaza militants. The operation is meant to crush Gaza militants who have been terrorizing southern Israel with increasingly menacing rocket fire.

In launching the campaign on Saturday, Israel made it clear that no one in Hamas was immune, and the air attack on the eight-story apartment building where Nizar Rayan lived sent that message home.

The airstrike blew a huge hole in the side of the building and sent a thick plume of smoke into the air. Nine other people, including two of Rayan's four wives and four of his 12 children, also died, Palestinian health officials. The Muslim faith allows men to have up to four wives.

Hamas leaders went into hiding before Israel launched its operation, but he was known for openly defying Israel.

Hamas threatened to take revenge against Israeli soldiers who were massed along the border with Gaza, waiting for a signal to invade.

"We are waiting for you to enter Gaza to kill you or make you into Schalits," it said. Israeli Sgt. Gilad Schalit was seized in a cross-border raid by Hamas-affiliated militants 2 1/2 years ago and remains in captivity in Gaza.

Rayan, 52, ranked among Hamas' top five decision-makers. A professor of Islamic law, he was known for his close ties to the group's military wing and was respected in Gaza for donning combat fatigues and personally participating in clashes against Israeli forces. He sent one of his sons on an October 2001 suicide mission that killed two Israeli settlers in Gaza.

More than 400 Gazans have been killed and some 1,700 have been wounded since Israel embarked on its aerial campaign, Gaza health officials said. The U.N. says the Gaza death toll includes more than 60 civilians, 34 of them children. Three Israeli civilians and one soldier have also died in rocket attacks that have reached deeper into Israel than ever before, bringing one-eighth of Israel's population within rocket range.

Throughout the day, huge blasts had rocked cities and towns across Gaza as Israeli warplanes went after Gaza's parliament building, militant field operatives, police and cars. The military said aircraft also bombed smuggling tunnels along the Gaza-Egypt border, part of an ongoing attempt to cut off Hamas' last lifeline to the world outside the embattled Palestinian territory.

Israel launched the offensive last Saturday after more than a week of intense Palestinian rocket fire that followed the expiration of a six-month truce.

So far, the campaign to crush rocket fire on southern Israel has been conducted largely from the air. But military spokeswoman Maj. Avital Leibovich said preparations for a ground operation were complete.

"The infantry, the artillery and other forces are ready. They're around the Gaza Strip, waiting for any calls to go inside," Leibovich said.

Israeli Cabinet ministers have been unswayed by international calls to end the violence, which is to include a whirlwind trip around the region next week by French President Nicolas Sarkozy.

Instead, they authorized the military to push ahead with its campaign against militants, who fired more than 30 rockets into Israel by late Thursday afternoon, according to the military. No injuries were reported, but an eight-story house in Ashdod, 23 miles (37 kilometers) from Gaza, was hit by a rocket that pierced through two floors.

Israeli Prime Minister Ehud Olmert told a meeting of mayors of southern Israeli communities Thursday that Israel would not shy from using its vaunted military power.

"We have no interest in a long war. We do not desire a broad campaign. We want quiet," Olmert said. "We don't want to display our might, but we will employ it if necessary."

Ordinary Israelis are not eager to see the operation expand beyond the air-based campaign, a poll Thursday showed.

The survey of 472 people showed that 52 percent want the air assault to continue, while only 19 percent wanted to see a ground offensive. Twenty percent favored a truce.

The same poll showed dovish and centrist parties would get 60 seats in Israel's 120-seat parliament if elections were held today, up from 53 before the operation. The big winner was Labor, led by Defense Minister Ehud Barak, the Gaza operation's mastermind. Hardline and religious parties dropped from 65 to 60. The Dialog company poll had a margin of error of 4.6 percentage points.

In five days of raids, Israeli warplanes have carried out some 500 sorties against Hamas targets, and helicopters have flown hundreds more combat missions, a senior Israeli military officer said Wednesday.

Earlier this week, Olmert rebuffed a French proposal for a two-day suspension of hostilities. But at the same time, he seemed to be looking for a diplomatic way out, telling U.S. Secretary of State Condoleezza Rice and other world leaders that Israel wouldn't agree to a truce unless international monitors took responsibility for enforcing it, government officials said. They spoke on condition of anonymity because the talks were confidential.

International intervention helped Israel to accept a truce that ended its 2006 war with Lebanese Hezbollah guerrillas, when the U.N. agreed to station peacekeepers to enforce the terms. This time, Israel isn't seeking a peacekeeping force, but a monitoring body that would judge compliance on both sides.

The idea was floated before the offensive but did not gain traction because of the complications created by the existence of rival Palestinian governments in the West Bank and Gaza, defense officials said.

Gaza has been under Hamas rule since the militant group overran it in June 2007; the West Bank has remained under the control of moderate Palestinian President Mahmoud Abbas, who has been negotiating peace with Israel for more than a year but has no influence over Hamas. Bringing in monitors would require cooperation between the fierce rivals.

An Abbas confidant said the Palestinian president supported the notion of international involvement. "We are asking for a cease-fire and an international presence to monitor Israel's commitment to it," Nabil Abu Rdeneh said.