BEIT LAHIYA, Gaza Strip -- A remote-controlled bomb exploded under a U.S. diplomatic convoy Wednesday, ripping apart an armored van and killing three Americans in an unprecedented deadly attack on an official U.S. target.\nIn a strongly worded statement, President Bush blamed Palestinian officials for the attack, which wounded another American. "Palestinian authorities should have acted long ago to fight terror in all its forms," Bush said.\nPalestinian officials condemned the bombing and promised to help the investigation. But they will likely now come under intensified U.S. pressure to take action against militants.\nIf Palestinian militants were to blame, it could signal a dramatic change in strategy. While targeting Israeli soldiers and civilians for years, the main militant groups Hamas and Islamic Jihad have not attacked U.S. officials -- apparently to avoid a harsh retribution from the Americans and the anger of Palestinian officials trying to work with Washington.\nBoth groups repeated their stance Wednesday that they don't attack Americans, and there was no claim of responsibility for the bombing.\nThe attack targeted a convoy of U.S. Embassy diplomats heading to Gaza to interview Palestinian candidates for a Fulbright scholarship, Bush said. The three dead and the wounded man were American security personnel working on contract with the embassy, said U.S. ambassador Dan Kurtzer.\nThe U.S. Embassy advised U.S. citizens to leave the Gaza Strip after the attack.\nPalestinian leader Yasser Arafat condemned the bombing as an "awful crime." The Palestinian prime minister, Ahmed Qureia, called Secretary of State Colin Powell to express his condolence and promise swift action.\nAn FBI legal attache is investigating, the FBI said. A team of investigators who photographed the charred van was pelted with rocks by Palestinians and had to cut short the visit.\nMeanwhile, Israel announced orders to expel three Palestinian militants from the West Bank to the Gaza Strip. The decision came after it issued similar orders a day earlier against 15 other Palestinians -- raising criticism from the Palestinians and human rights group.
Wednesday's bomb detonated around 10:15 a.m. (4:15 a.m. EDT) as the three-car convoy, escorted by Palestinian police, was heading south on Gaza's main road just after entering the Gaza Strip from Israel. In Washington, State Department spokeswoman Brooke Summers said the blast came from a "previously planted explosive device."\nAn AP reporter saw a gray wire with an on-off switch leading from the scene of the attack to a small concrete building at the side of the road.\nAfter the first two cars -- including the police escort -- went by, the third car had just passed when the blast went off near a gas station, said Mohammed Radwan, a Palestinian taxi driver who was at the station at the time.\n"The first two cars drove quickly and stopped far from the explosion. Palestinian security people jumped out of the car and rushed to the car that had blown up ... I saw two people covered with blood lying next to the car," he said.\nThe blast gouged a deep crater into the unpaved stretch of road. The attack tore the van in half and flipped it over, leaving the wreckage twisted with the tires up in the air. The pavement was stained with blood and littered with bits of flesh that were collected by Palestinian paramedics.\nPalestinian security sources said they had ruled out the major Palestinian factions and were focusing their investigation on some small groups that receive funding from abroad, possibly Iran.\nThe United States and Israel have been pressing the Palestinians for months to dismantle militant groups. The focus recently has been on trying to get all the Palestinian security forces _ some of which are controlled by Arafat -- under the control of his prime minister to carry out a crackdown. Arafat, however, has resisted handing over security powers.\n"The failure to create effective Palestinian security forces dedicated to fighting terror continues to cost lives," Bush said in a statement. "There must be an empowered prime minister who controls all Palestinian forces -- reforms that continue to be blocked by Yasser Arafat."\nThe attack was the second to target U.S. officials in Gaza, according to Kurtzer. The previous attack, on a bulletproof car in Gaza in June, did not cause any injuries, he said, providing no further details. In June, the U.S. government announced it had received "credible reports" of plans to kidnap U.S. citizens in Gaza.\nAttacks on U.S. targets have taken place in other other Arab countries, including Lebanon, Saudi Arabia and now Iraq. In October last year, an American administrator for the U.S. Agency for International Development was gunned down in the Jordanian capital, Amman, in an assassination thought linked to the al Qaeda network.\nBut in the bloody conflict between Israel and the Palestinians, there has been an unofficial policy of "hands off" the Americans -- though 49 Americans, many with dual citizenship, have been caught in the crossfire in the past three years of fighting.\nHamas and Islamic Jihad reiterated Wednesday that they have no interest in taking aim at non-Israeli targets.\n"The Palestinian resistance believes that its enemy is the one who has occupied its land, who has killed the people of this land," Sheikh Adnan Assfour, a Hamas leader from Nablus, said in a statement faxed to The Associated Press.\nIslamic Jihad spokesman Nafez Nazzam said, "Our battle is with the occupiers only ... In the land of Palestine, it's not proper to target Americans nor any other nations."\nBut resentment against the United States has been growing steadily, with many Palestinians complaining that Washington sides with Israel.\nU.S. convoys of armored black and silver Chevrolet Suburbans travel in Gaza almost daily and usually take the same route on the main north-south road in the strip. The convoys are easily identifiable: They are escorted by Palestinian police and have diplomatic plates. The color and make of the vehicles are unique to U.S. officials.\nThe State Department advisory Wednesday recommended that "all U.S. citizens depart the area as expeditiously as possible." Kurtzer said between 200 to 400 Americans, some of them of Palestinian descent, work in the Gaza Strip, many for aid groups.\nIsraeli officials said the attack underscored the need to dismantle Palestinian militant groups.\n"What happened is evidence that no one is immune, unfortunately, to Palestinian terrorism," said Zalman Shoval, an adviser to Prime Minister Ariel Sharon.
