Israel bombed the home of a Hamas (search) leader Wednesday, killing his eldest son and a bodyguard in retaliation for two homicide bombings. The Palestinian prime minister-designate said he will quickly form a government to forestall even harsher Israeli reprisals.

Israeli Prime Minister Ariel Sharon (searcharrived home early Thursday after cutting short a visit to India, planning to convene senior Cabinet ministers and security commanders for urgent talks after the two blasts killed 15 Israelis.

A security official said the Israeli leader would consider far-reaching options, such as forcing Yasser Arafat (searchinto exile or ordering a large-scale invasion of the Gaza Strip.

In one of the most strident comments yet from the mainstream Israeli press, the English-language Jerusalem Post called in an editorial for killing Arafat "because the world leaves us no alternative."

Meanwhile, Israeli forces operating in Ramallah blew up two houses Thursday -- one south of Arafat's compound and the other in the suburb of Beitunia. Both blasts could be heard at the compound, where tension was high but no unusual activity was seen. Israel is in control of the West Bank Palestinian town.

The spiral of violence drew calls for retaliation from Israelis and Palestinians alike. The Islamic militant group Hamas claimed responsibility for Tuesday's twin homicide attacks and said it would now begin targeting Israeli homes and high-rises in response to Wednesday's airstrike on the home of senior Hamas leader Mahmoud Zahar.

A half-ton bomb flattened the house, wounding Zahar and killing his eldest son and a bodyguard. It marked the first time a Hamas leader has been attacked in his home, an escalation of Israel's campaign against the group. Twenty-five people were wounded, including Zahar's wife and a daughter.

In the West Bank, Palestinian parliament speaker Ahmed Qureia accepted the job of prime minister after several days of wavering, his decision to accept Arafat's offer apparently rushed by fears that a power vacuum would tempt Israel to intensify military strikes.

Qureia said he would form a crisis Cabinet of no more than eight ministers and seek parliament's approval Thursday.

President Bush urged Qureia to crack down on militants and said the United States has not abandoned its "road map" peace plan despite Tuesday's homicide bombings, which killed 15 people and wounded dozens.

"The road map is still there. The fundamental question is whether or not people, peaceful people, will be on the road," Bush said.

In the northern West Bank late Wednesday, Israeli soldiers shot and killed a Palestinian who was trying to damage a security fence between the West Bank and Israel, the military said.

Hamas' military wing claimed responsibility for the Tuesday homicide bombings, saying they were "the beginning of our retaliation for the enemy's crimes against our people."

A spokesman for the Al Aqsa Martyrs' Brigade, loosely linked to Arafat's Fatah movement, said his group also was behind one of the bombings outside an army base near Tel Aviv. That raised fears that there might be a third homicide bomber roaming Israel.

The explosion at the bus stop near Tel Aviv killed eight soldiers, and the second blast five hours later killed a security guard and six patrons at a Jerusalem coffee house. Dozens of bystanders were wounded.

Among the dead at the Hillel Cafe were two U.S. citizens -- a doctor who headed a Jerusalem hospital emergency room and his daughter, who was to have been married Wednesday. Instead of a wedding, a funeral was held for both.

The Israeli military said it will press ahead with its "all-out war" on Hamas. Israel has killed 13 Hamas members and six bystanders in targeted attacks in the past three weeks, and Hamas said the homicide bombings came in retaliation for strikes against its leaders.

Some 12 hours after the attack in Jerusalem, Israeli warplanes bombed the home of Zahar, whom Israel says helped decide on homicide bombings that have killed hundreds.

"This crime only is going to escalate the process of resistance," Zahar told The Associated Press from his hospital bed, with three bodyguards standing watch.

Zahar, 58, had a bruise under his left eye and a bandaged hand. He said he was sitting in his house when the F-16s swooped over and dropped the bomb.

Zahar also lashed out at the United States and European countries, telling the Arab satellite TV station Al-Jazeera that "the Arab people should rise up and threaten America's interests everywhere."

Some 3,000 mourners carried his son's body through the street as Hamas supporters fired rifles into the air.

In Gaza Wednesday night, Israeli tanks fired five shells near a Palestinian police post, but no one was injured, Palestinian police and rescue workers said.

The army said shells were fired at a Palestinian who tried to infiltrate Israel several miles away. The Palestinian escaped, the army said.

In Hebron early Thursday, Israeli troops demolished the home of Abdullah Kawasme, formerly the head of the Hamas military wing in the West Bank city, who was killed by the army several months ago.

Also Thursday, Israeli forces destroyed 14 structures in the Rafah refugee camp on the Gaza-Egypt border, Palestinian security officials said. Israeli military sources said the buildings were used by Palestinians to fire weapons at Israeli positions. Six Palestinians and two Israeli soldiers were wounded.

Israeli troops also arrested Raed Barghouti, a Hamas operative, in the West Bank town of Ramallah. Palestinian security officials said he apparently had a role in the bombings.

The violence underscored the collapse of the U.S.-brokered peace efforts and came amid political uncertainty after the resignation of Palestinian Prime Minister Mahmoud Abbas.

Qureia, a moderate with close ties to Arafat, said he would make security his top priority, but he stopped short of saying he would clamp down on Palestinian militants, as demanded by Israel and the United States.

Qureia has urged Israel to lift its siege on Arafat's West Bank headquarters and to end the targeting of Palestinian extremists, two areas in which the Israelis appear unlikely to compromise.