Israeli Prime Minister Ariel Sharon indefinitely postponed a Washington trip seen as crucial for launching the "road map" plan, and instead convened his Cabinet to weigh a response to the bombing that also wounded 20 passengers.

At a four-hour Cabinet meeting Sunday, several ministers renewed calls for Yasser Arafat's expulsion, but Sharon said Israel was better off not having the Palestinian leader tour world capitals. For more than a year, Arafat has been confined to the West Bank town of Ramallah by Israel.

Israel "will continue to fight terror everywhere, at any time and in any way possible," the Cabinet said in a statement.

In a routine response, the Israeli military sealed off the West Bank and Gaza Strip, a step that meant little because Palestinians already are subject to stringent travel bans.

A senior government official, who spoke on condition of anonymity, said that foreign diplomats who declare their intention to meet Arafat will not be received by Israeli officials, an attempt to further isolate the Palestinian leader.

Sunday's bus blast was one of four Palestinian attacks within 11 hours, apparently aimed at derailing the peace plan. The three suicide bombings and a shooting left nine Israeli civilians and five Palestinian assailants dead.

The attacks were timed to coincide with the first Israeli-Palestinian summit since 2000, held late Saturday between Sharon and Palestinian Prime Minister Mahmoud Abbas.

Israel held Arafat responsible for the attacks, charging that he continues to encourage militants.

The Abbas government condemned the bombings, and said it was serious about ending violence. Arafat, in a telephone interview with the Fox news channel, denounced "all kinds of ... killing" and said he would not agree to be expelled under any conditions.

Israel demands tough measures against the violent groups ahead of any other peace moves, though the peace plan -- a three-stage prescription for ending violence and setting up a Palestinian state by 2005 -- calls for parallel steps. Sharon was to have discussed his reservations with President Bush on Tuesday.

In Washington, the Bush administration condemned Sunday's attack.

US Secretary of State Colin Powell issued a statement calling on the Palestinians "to begin to take immediate and decisive action to eradicate the infrastructure of terrorism and violence that has wrought such tragic bloodshed for both Palestinians and Israelis and has undermined Palestinian aspirations."

U.N. Secretary-General Kofi Annan also urged Israelis and Palestinians not to let those responsible for the latest "murderous attacks" against Israelis hijack the peace process.

In a toughly worded statement, Annan called on both sides to fully implement the internationally backed "road map" to peace.

Israel's vice premier, Ehud Olmert, accused the international community, particularly the European Union, of undercutting Abbas by refusing to join Israel and the United States in a boycott of Arafat, who they say is tainted by terrorism.

"Many European governments are sending signals that strengthen Yasser Arafat," Olmert told Israel TV's Channel 1. "As a result, this (Abbas' government) is a paralyzed government ... and we can't even put it to the test of whether it wants to fight terror or not."

One idea apparently being considered by the Cabinet was for Israel to declare that no progress on the peace plan can be made until the international community understands that Arafat must be stripped of influence.

Sunday's bus bombing, the 93rd in 32 months of fighting, went off just before 6 a.m. at a busy intersection on the outskirts of Jerusalem, at the start of morning rush hour on what is a regular workday in Israel.

The attacker, a 19-year-old from the West Bank city of Hebron, was disguised as an observant Jew with a skullcap and white prayer shawl. Just seconds after boarding the two-sectioned bus, he detonated nail-studded explosives strapped to his body. The gush of metal and fire tore through the leg of the driver, who lost control of the vehicle.

The bodies of the dead remained sitting upright in their seats, including that of a woman with short dark hair whose head slumped back and whose legs were still crossed. One man's body, heaved by the blast, leaned from a broken window.

The seven dead included four new immigrants from the former Soviet Union. The wounded passengers included six soldiers returning to their bases after weekend leave.

Hamas did not issue a formal claim of responsibility, but Bassem Jamil Tarkrouri, a Hamas activist, was identified by relatives as the assailant. Hamas has carried out dozens of bombings in recent years to try to derail peace efforts.

About half an hour after the bus attack, a second attacker blew himself up on the city's outskirts, apparently after he failed to penetrate road blocks set up in the wake of the first attack. No one else was hurt.

In a suicide bombing Saturday evening, just before the Sharon-Abbas summit, a Hamas assailant killed an Israeli couple in a downtown square in Hebron.

Israeli security sources said Sunday on condition of anonymity that all three bombers came from the same Hebron cell of Hamas.

In other incidents Sunday: