At least 15 Palestinians were killed today -- eight in one incident -- in the deadliest fighting between Hamas and Fatah since the rivals formed a unity government to end bloodshed threatening to spill into civil war.
Gunbattles raged into the night as masked fighters vied for control of the Gaza streets. Hamas fully deployed its armed wing in a sign it was preparing for wider conflict.
Palestinian gunmen take up their positions on a street in Gaza today. Image: Reuters.
For many Palestinians, the violence was particularly disturbing, coming on the "Nakba", an annual day of national reflection over shared suffering in the conflict with Israel.
Palestinian Prime Minister Ismail Haniyeh of Hamas convened an emergency meeting of faction leaders in a bid to "put an end to the fighting". Egypt and Saudi Arabia pressed Hamas and President Mahmoud Abbas's Fatah faction to rein in their forces.
A Fatah spokesman said Hamas gunmen had killed eight members of Abbas's Presidential Guard in an attack near Karni Crossing, Gaza's main commercial entry point into Israel.
The Fatah-affiliated guardsmen were en route to help comrades under assault by Hamas at a training base near the crossing when Israeli forces across the frontier opened fire at them, according to the spokesman, Tawfiq Abu Khoussa.
"Some of the vehicles overturned and some of the men were wounded. The forces retreated but they were ambushed by Hamas gunmen, who finished them off," he said.
An unidentified Fatah security man who said he had been wounded in the incident told Palestinian television: "They came and shot the wounded. They left me, believing I was dead."
Hamas's armed wing denied the allegation, blaming the deaths on Israel and accusing Fatah of killing one of its commanders earlier on Tuesday. The Israeli military said it had fired at two gunmen who approached the border fence, hitting one of them.
Raising tensions further, Hamas said one of its senior figures was "executed" at a checkpoint manned by Fatah fighters. Fatah had no immediate comment.