Jerusalem ? Palestinian gunmen killed three Israelis and wounded four others Sunday in two drive-by shootings near Jewish settlements in the West Bank. In a separate incident, Israeli border policemen killed a Palestinian militant.

The killings came days before a visit to Washington by Palestinian President Mahmoud Abbas, underlining the fragility of an 8-month old truce that has sharply reduced violence but not ended it.

The attacks in the West Bank were the deadliest there since Israel completed a withdrawal from the Gaza Strip last month. Israeli security officials had warned that Palestinian militants would shift the focus of their attacks to the West Bank after the pullout.

Gunmen riding in a car opened fire at a hitchhiking post near the Israeli settlement bloc of Gush Etzion in the southern West Bank, killing three settlers and wounding three people, the army said.

Shortly after the attack, gunmen opened fire from a car at a group of Israeli teenagers walking on a road near the settlement of Eli in the central West Bank, wounding one seriously.

Al Aqsa Martyrs’ Brigades, the armed wing of Fatah, the dominant Palestinian faction, claimed responsibility for the attacks, calling them retaliation for Israel’s killing of a leader of the group earlier this month.

At a meeting between Israeli Defense Minister Shaul Mofaz and security officials after the attacks, they decided to restore checkpoints and roadblocks that had been removed in recent months from the outskirts of Palestinian towns and villages, to ban Palestinian cars from main West Bank roads used by Israeli settlers and to step up arrests of suspected militants, Israeli television stations reported.

Mofaz told reporters that there could be no progress in peace efforts without a Palestinian crackdown.

“The Palestinian Authority has to move from words to deeds,” Mofaz said. “We will not be able to continue this process if the Palestinian Authority will not move to real action against the terror organizations.”

Earlier Sunday, Nihad Abu Ghanem, 27, a member of the armed wing of the militant Islamic Jihad group, was killed by Israeli undercover border policemen in a shootout near the Palestinian city of Jenin in the northern West Bank.

Palestinian and Israeli accounts of the clash described it as an unplanned encounter.

The militant, who was driving to Jenin, stopped his car and opened fire when he spotted two border police vehicles at a junction near the city, according to the reports. The border policemen, who were on routine patrol, returned fire and killed the militant, the army said.