Three Palestinians were killed in the northern West Bank city of Nablus yesterday in two separate clashes between Israeli troops and stone-throwing demonstrators, Palestinian medics and witnesses said.

Early in the morning, Amjad Bilal al-Masri, 15, was killed by two bullets to the chest when Israeli troops opened fire on stone-throwing demonstrators in the city's old quarter, the scene of repeated search operations by the Israeli military over the past two weeks.

An Israeli military source said soldiers on patrol in Nablus had opened fire on a group of Palestinians "after they were attacked with stones".

"One Palestinian was hit," the source said, adding that the soldiers had fired because they "felt themselves in danger".

An hour later, Amer Arafat, 18, and Rawahi Shuman, 25, were pronounced dead on arrival in hospital after coming under Israeli fire.

Witnesses said the two men were hit in the chest when troops fired live bullets to disperse stone-throwers.

An Israeli army spokesman said the soldiers had hit two Palestinians, one of them "armed" and the other preparing to throw a Molotov cocktail.

They had also fired on a third Palestinian who had detonated a bomb as a patrol passed but it was unclear whether he had been hit, the spokesman said. There were no casualties in the blast.

Two Palestinians had been wounded, one of them critically, in a similar Israeli shooting in the city Friday evening. That incident followed the detonation of a bomb as an Israeli jeep passed.

Nablus has been under Israeli military curfew for nine straight days and is the only West Bank city still under formal blockade, although ubiquitous roadblocks in the territory still make travel for Palestinians difficult.

Late Friday, Israeli troops pushed back into the town of Jenin farther north, scarcely 24 hours after lifting a four-month blockade there.

Around 15 jeeps and tanks moved into the city and began surrounding several houses in the eastern sector, provoking clashes with Palestinian gunmen, Palestinian security sources and witnesses said.