Israeli troops snatched a top Hamas fugitive in a roadside ambush Monday and raided a stronghold of the Islamic militant group, killing two Palestinians and blowing up the house of a suspected bombmaker.

The Israeli strikes came in response to a deadly Hamas attack on an Israeli tank over the weekend. Israel said it will intensify its hunt for Hamas militants, who have carried out many of the bombings and other attacks against Israeli targets in the past 29 months of fighting.

The Hamas fugitive, Riyad Abu Zeid, was seriously wounded in the Israeli raid and later died at an Israeli hospital, according to Hamas officials and Israeli radio reports. Witnesses said Abu Zeid's car was ambushed by undercover troops hiding in a van loaded with vegetables.

Israeli Defense Minister Shaul Mofaz said Sunday that troops would strike harder against Hamas, including with targeted attacks on militants. On Saturday, Hamas activists set off a roadside bomb that hit a tank and killed four soldiers.

"There will be no immunity, there will be no sanctuary, not in Gaza ... not in any other place," said Raanan Gissin, an aide to Israeli Prime Minister Ariel Sharon.

The Israeli daily Haaretz said troops were poised for a major strike in Gaza, but will stop short of reoccupying the strip, home to more than 1 million Palestinians.

In all, 13 Palestinians were killed in the West Bank and Gaza Strip during a 24-hour period from midday Sunday to midday Monday, including six Hamas members who died in a mysterious explosion on Sunday.

The violence erupted amid new efforts to negotiate a cease-fire and get peace talks back on track. Israel and the Palestinians sent delegations to London on Monday to meet with members of the so-called Quartet of Mideast mediators — the United States, the European Union, the United Nations and Russia — who are trying to draft a plan to end the fighting and establish a Palestinian state.

Israeli officials did not rule out the possibility that the Israeli and Palestinian delegations would meet in London. It would be the first such meeting in many months.

Abu Zeid, a leader of Hamas' military wing Izzedine al-Qassam, was captured just before noon Monday. At the time, Abu Zeid was traveling by car on Gaza's coastal road, accompanied by at least one bodyguard, witnesses said.

A Palestinian taxi driver, who witnessed the incident, said shots were fired at the Honda from a blue van parked by the side of the road. The taxi driver, who only gave his first name, Mohammed, said one of the men in the Honda died at the scene. The driver said a military ambulance took away the driver and passenger, as well as their belongings. The Honda's windshield was riddled by bullet holes, and a pool of blood covered the front passenger seat.

The Israeli military declined comment.

Earlier Monday, about 35 tanks, escorted by helicopter gunships, entered the Sheik Radwan neighborhood in Gaza City.

Troops surrounded the five-story home of Ahmed Ghandour, who is a top aide to Hamas bombmaker Adnan al-Roul and is also believed to be responsible for planning the weekend attack on the Israeli tank that killed four soldiers.

Troops ordered everyone out of the building and adjacent homes and took the men away, witnesses said. Then soldiers sent dogs inside to see if anyone was left behind. Neighbors were ordered to leave their windows open to help absorb the shock of the explosion, the witnesses said.

The army said Palestinian gunmen attacked soldiers, who returned fire. A Palestinian policeman and a suspected militant were killed during the five-hour incursion, hospital officials said. Five civilians, including a doctor, were wounded, the officials said.

Israel has been blowing up houses of suspected militants for several months in an attempt to deter militants from attacking Israelis. Palestinians and human rights groups say such actions violate international law and constitute collective punishment.

On Sunday, six Hamas activists, including an aide to another top bombmaker, Mohammed Deif, were killed in an explosion in another part of Gaza City. It remained unclear Monday whether the blast was caused inadvertently by militants handling explosives or whether Israel targeted the group.

Hamas said in a statement that the six were killed when a small pilotless plane they had been testing blew up. The group blamed Israel for the explosion, but did not give evidence to back its charges. In the past, a number of militants have been killed while building bombs. The Israeli military declined comment. Gissin said Israel has been aware for some time that Hamas is trying to use such a plane, or drone, to carry out an attack.

A Hamas leader, Abdel Aziz Rantisi, said Monday that the group would retaliate for the deaths of the six activists. "The crime against our fighters will not pass without ... punishment from Hamas and the Palestinian people," he said.