JERUSALEM -- Palestinian gunmen killed three Israelis and wounded four others yesterday in drive-by shootings in the West Bank that officials on both sides said would probably hamper efforts to begin peace negotiations.

Only days before Palestinian leader Mahmoud Abbas is scheduled to meet President Bush in Washington, the armed wing of his Fatah movement asserted responsibility for the shootings, the most severe of which occurred at a bus stop in a bloc of settlements south of Jerusalem popular with hitchhikers. The Israeli death toll -- which Israeli media reports said included two women, cousins aged 23 and 21, and a 15-year-old boy -- was the highest as the result of a Palestinian attack since July, when a suicide bomber killed five people in the city of Netanya.

The second militant attack took place near the settlement of Eli in the northern West Bank, relatively far from the first shooting.

The Al-Aqsa Martyrs Brigades, Fatah's armed wing, is a diffuse militia whose many regional commands often operate on their own. But Israeli officials sharply criticized Mr. Abbas, known commonly as Abu Mazen, for failing to disarm the group and other more radical ones, such as Hamas, an Islamic movement that does not recognize Israel's right to exist.

"Not only does Abu Mazen not do what he says he'll do in regards to Hamas, but he can't control his own people," said Zalman Shoval, an adviser to Israeli Prime Minister Ariel Sharon and a former ambassador to the United States.

Palestinian officials also worried that the attack could cast a shadow over Mr. Abbas' meeting with Mr. Bush, scheduled for Thursday, at a time when the Palestinian leader is hoping to enlist U.S. help in dealing with Mr. Sharon.

"I think whoever did this had in mind undermining the meeting" with Mr. Bush, Saeb Erekat, the chief Palestinian negotiator, said of yesterday's attacks. "It's undermining our efforts to revive the peace process, and it's also undermining Abu Mazen's political standing."

The late afternoon shootings came soon after an Israeli police patrol near the northern West Bank city of Jenin killed a military commander of the Islamic Jihad, a smaller faction that like Hamas is at war with Israel. Israeli military officials said a special police unit came under fire while on patrol and responded by killing the gunman.