A large crowd quickly gathered around the bodies lying in Salam Street in Hebron. Some of the bystanders kicked and spat at the corpses. The three men had been shot in the head, with their hands tied behind their backs.

The Bush administration later denounced the killings, calling the incidents "troubling" and warning they undermined hopes for a Palestinian state.

"There are Palestinians who are killing Palestinians and it's troubling, and it's not helpful to the creation of a stable Palestinian state," White House spokesman Ari Fleischer told reporters.

"All these issues need to be resolved in a way that Israel and Palestine can live together in peace as nations that respect each other and honor each others' sovereignty," he added.

In raids overnight Monday in the West Bank cities of Qalqilya, Hebron and Bethlehem, IDF forces arrested 42 Palestinians.

The killings in Hebron came only a day after Al Aqsa militiamen opened fire on three alleged informers in a downtown square in the West Bank town of Ramallah. The three were seriously wounded, and a large crowd watched as they lay on the ground, writhing in pain.

Bystanders tried to block approaching ambulances, but the three were eventually taken to a city hospital where one later died.

The leader of the Fatah-related Tanzim militia in Hebron, Marwan Zaloum, was killed close to midnight Monday in a helicopter-launched IDF missile attack. Two missiles fired at Zaloum's car also killed his assistant, Samir Abu Rajoub, a member of Force 17 - Palestinian leader Yasser Arafat's personal guard detail.

Military sources reported that Zaloum is believed to be responsible for numerous shooting attacks and bombings, including the March 2001 murder of Shalhevet Pas, a 10-month-old infant killed by a Palestinian sharpshooter in Hebron.

Palestinian security officials said Zaloum was on a list of 33 activists the Israelis turned over to the Palestinians several months ago, demanding that they be arrested.