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A Palestinian homicide bombing at a bus stop outside Tel Aviv killed four people Thursday just minutes after an Israeli helicopter fired missiles at a car in Gaza, killing a senior Islamic Jihad (search) commander and four others.

The attacks were the first of their kind in more than two months and were likely to lead to a wave of retaliatory violence and damage new efforts to restart the Israel-Palestinian peace process.

Palestinian officials and Egyptian mediators have been struggling to convince militants to halt attacks and get Israel to forgo such targeting killings of militant leaders. Palestinian officials condemned both attacks Thursday and called for renewed peace talks. Israeli leaders said the homicide bombing proved why such airstrikes were needed and pledged to continue fighting militants.

The homicide bombing took place during the busy evening rush hour at a bus stop at the Geha junction outside Tel Aviv where Palestinian workers routinely wait for people to pick them up for potential jobs, police said.

The bomber approached the bus stop and blew himself up, killing two women and another man, said Israeli Police Commissioner Shlomo Aharonishki (search). Another woman died later in a hospital, police said. At least 13 other people were wounded.

An official who saw the bodies of the dead said he believed they were Israelis. Tel Aviv district police commander Yossi Sedbon told Israel Radio that hoped "the (terrorist) cell" would be apprehended soon, indicating that the bomber had accomplices. He said a court-ordered news blackout was imposed on the investigation.

The Popular Front for the Liberation of Palestine (search) claimed responsibility in a call to The Associated Press, saying it was in retaliation for the killing of two of its members last week. The group identified the bomber as Said Hanani, 18, from the village of Beit Furik, east of the West Bank city of Nablus.

The bombing was the first such attack on civilians since an Islamic Jihad homicide bomber blew herself up on Oct. 4 at a restaurant in the northern Israeli city of Haifa, killing 21 people.

The U.S. government condemned the homicide attack. "The United States reiterates the absolute need for urgent action by the Palestinian Authority (search) to confront terror and violence," State Department spokesman Richard Boucher said.

A few minutes before the bombing Thursday, Israeli helicopters fired two missiles at a car driving between Gaza City and the nearby Jebaliya refugee camp, killing the top commander of the Islamic Jihad group in Gaza, Mekled Hameid, 39, and four others — two Islamic Jihad militants and two bystanders, militants said.

Hospital officials said 14 people were wounded, three seriously.

Defense Minister Shaul Mofaz said Hameid was targeted because he was planning a "mega-terror attack." Mofaz did not elaborate. Israeli military sources would say only that the attack was to be inside Israel.

Israeli army spokesman Capt. Jacob Dallal described Hameid as a "ticking bomb." He told AP that Hameid "was behind a long, long list of terror attacks, and he was in the midst of planning a major attack."

The targeted car was burned black, its windows shattered. Nearby buildings in the heavily populated neighborhood were damaged.

However, Palestinian witnesses said the Israelis apparently used a different kind of ordnance than in previous attacks, since the bodies were not burned in the explosion and there was not much shrapnel.

The raid was the first air strike of its type since Oct. 20, when an Israeli helicopter launched missiles at a car in the Nusseirat refugee camp in Gaza, killing 14 people, most of them bystanders. In that strike, the Israelis were chasing Palestinians who had tried to infiltrate into Israel, according to the military.

Such operations in the past often caused civilian casualties and have led to revenge attacks by militant groups.

At Gaza's Shifa Hospital, where the wounded were taken Thursday, masked Islamic Jihad militants promised "a severe retaliation" deep inside Israel.

The airstrike and homicide bombing came after clashes during a two-day military operation in Gaza's Rafah refugee camp left nine Palestinians dead. That operation, which ended Wednesday, led Palestinians to cancel a preparatory meeting for a planned summit between the two sides' prime ministers intended to speed up peace efforts.

"We condemn the targeting and killing of Palestinian and Israeli civilians and we call on Israeli government to resume a meaningful dialogue to a peace process," Palestinian Cabinet minister Saeb Erekat told AP.

The meeting between Israeli Prime Minister Ariel Sharon and Palestinian Prime Minister Ahmed Qureia was intended to reinvigorate the U.S.-backed "road map" peace plan, which envisions an end to three years of violence that has killed more than 2,600 Palestinians and about 900 Israelis.

The recent lull in homicide bombings had led many to believe Palestinian militants were observing an informal, unilateral cease-fire on attacks as part of Qureia's efforts to negotiate a formal truce.

Israeli officials said the reason for the lull was not that the militants were less active but that Israel had stopped them.

Since the Oct. 4 Haifa bombing, the military prevented 22 homicide bombing attempts and 13 other planned attacks, Dallal said.

The homicide bombing Thursday "further proves that Israel must stay one step ahead of Palestinian terrorism and take whatever steps are necessary to prevent terror before it strikes at innocent Israeli civilians," said David Baker, an official in Sharon's office.

Israeli Health Minister Dan Naveh blamed Yasser Arafat for the homicide bombing and pushed for Israel to expel the Palestinian leader. Several months ago Israel's Cabinet declared Arafat an obstacle to peace that must be removed, but intense U.S. pressure prevented an Israeli move against him.

Last week, Sharon said he was considering pulling out of parts of the West Bank and Gaza even without a deal with the Palestinians, and dismantling Jewish settlements in the areas Israel vacates.