Israeli troops opened fire on a car in the West Bank on Wednesday, killing four Palestinian militants, Palestinian medical officials said. The violence threw doubt on prospects for a cease-fire between Israel and Hamas.

Associated Press Television News video showed medical officials loading the bodies of the men into an ambulance.

The Israeli military had no immediate comment.

Palestinian security officials said one of the dead was the commander of Islamic Jihad in the Bethlehem area, Mohammed Shehadeh, and two others were also members of Islamic Jihad. The fourth belonged to the Al Aqsa Martyrs Brigades, a violent offshoot of Palestinian President Mahmoud Abbas' Fatah.

The shooting came shortly after the leader of the Hamas government in the Gaza Strip called for a cease-fire with Israel. Among his conditions was a halt to Israeli military operations in the West Bank. In the past, Gaza militants have claimed the right to retaliate against Israel for its operations in the West Bank.

Egypt and the United States have been trying to broker an agreement to stop daily rocket fire from Gaza into Israel and halt Israeli reprisal raids in Gaza. Other elements would be reopening the Gaza-Egypt border crossing and easing restrictions on shipments of vital products from Israel into Gaza. For several days, violence has significantly dropped.

However, the renewed West Bank clashes threw the deal into doubt.

Islamic Jihad leader Nafez Azzam in Gaza denounced the shooting.

"This new crime reflects the true face of the occupation," he said. "Killing still continues while they are talking about the possibility of bringing calm, but if they think that calm means Palestinian surrender, they are mistaken."

Israel Radio reported that the car was filled with arms and explosives, and the fugitives opened fire on the Israeli special forces. The report said the four had been on Israel's wanted list since 2000.