Associated Press Israeli medics and police officers evacuate a wounded woman from the site of a suicide bombing in downtown Jerusalem yesterday. A suicide bomber detonated his explosives just after midday, killing three people including himself, and injuring at least 30 people on a busy street that has been the scene of several previous attacks.

JERUSALEM - For the first time, a Palestinian woman launched a bomb attack yesterday, killing herself and an 81-year-old Israeli man and wounding at least a dozen people on a busy Jerusalem street.

Israeli police said they were not sure if the woman intended to kill herself or if the bomb exploded prematurely as she walked along Jaffa Street, the main commercial strip in west Jerusalem.

In Lebanon, the Al-Manar television station run by the militant Hezbollah movement said the bomber was Shinaz Amuri, a female student at Al-Najah University in the West Bank town of Nablus.

Israel accused Palestinian leader Yasser Arafat of "encouraging terrorism" and said it was prepared to respond to the bombing - the third major attack in an Israeli city in a week.

Vice President Dick Cheney said Arafat must "make a 100 percent good-faith effort to put an end to terrorism."

The blast next to a shoe shop blew out shop windows, set a store on fire and left victims sprawled on the pavement amid shards of glass, pieces of fruit, shoes and storefront mannequins.

"It sounded like half the street exploded," said Hama Gidon, a clothing store worker who was slightly injured. "All the mannequins went flying and I did too. People were falling, glass was flying everywhere."

More than 100 people were treated on the spot or taken to hospitals, though most suffered only from shock. Three people were seriously hurt and nine had moderate injuries, officials said.

Mark Sokolov, a U.S. citizen from Woodmere, N.Y., who survived the terrorist attack on the World Trade Center, was slightly hurt in yesterday's explosion along with his wife and two daughters.

"I heard a loud whoosh, like a bang, and I kind of saw things flying around a little bit, and then I realized I was able to get up and walk around," Sokolov told Israeli television.

Sokolov said he was on the 38th floor of the World Trade Center's south tower on Sept. 11 when a hijacked airliner hit the north tower. His office was evacuated, and he escaped before the south tower was hit.

No group immediately claimed responsibility for yesterday's attack, but Israel said it held Arafat ultimately responsible.

Arafat is "encouraging terrorism, he's sending (attackers) to Jerusalem," said Raanan Gissin, a spokesman for Israeli Prime Minister Ariel Sharon. "We will continue to systematically dismantle the terrorist infrastructure."

The Palestinian leadership, meanwhile, "strongly condemned the suicide attack" and called on President Bush to send Mideast envoy Anthony Zinni back to the region. However, Bush has been sharply critical of Arafat, and Cheney suggested on "Fox News Sunday" that Zinni will not return soon.

"At this stage, we need to see some positive signs that his return would do some good. And that means we've got to see some positive results out of Arafat," Cheney said.

Arafat must "make a 100 percent good-faith effort to put an end to terrorism," he said. "So far he hasn't done that."

The Palestinian leadership on Saturday called for a halt to all attacks against Israel. However, several Palestinian groups have said recently that they would no longer observe a cease-fire declared by Arafat in December.

Israel has dismissed the Palestinian cease-fire calls as meaningless and says Arafat has simultaneously been encouraging militants.

In a speech Saturday, Arafat said Palestinians were "facing a military crisis, but despite all this, no one has complained of the suffering. They have said, 'God is great, and jihad, jihad, jihad."'

"Jihad" is an Arabic word that can be translated as "resistance," "struggle," or "holy war," and the context was not clear in Arafat's statement.

Just south of Jerusalem on yesterday, an angry Palestinian crowd stormed a prison in Bethlehem and freed seven prisoners belonging to Hamas and Islamic Jihad, the two groups that have carried out past suicide bombings, Palestinian security officials said.

Palestinian security officers did not want to use force with the crowd and did not try to stop them, a Palestinian security official said.