Security sources said the wounded were all members of preventive security loyal to the Fatah faction of the Palestinian president hurt in fighting on Thursday afternoon.

A Hamas commander on the scene blamed the security services for starting the troubles, which came as Palestinian leaders called for an end to the bloodshed caused by increased fighting between Fatah and Hamas paramilitaries.

Yussuf al-Zahar said: "Members of preventive security have provoked a member of our force and opened fire, and our forces returned fire."

The violence was the latest in a string of gunfights, assassinations and bombings between members of the Fatah-controlled security forces and a new security unit formed by Hamas to counter Fatah's control of the streets.