Fatah, Hamas gunmen clash in Gaza

But the friction threatened to boil over again with neither side backing down from its key demands in vying for control of the Palestinian security forces.

The two sides traded gunfire and hurled stones and firebombs Saturday, escalating a fierce power struggle between the militant and moderate factions. Abbas said Saturday he would not allow the accusations to plunge the Palestinians into civil war.

In a meeting that began late Saturday, Hamas and Fatah officials agreed to calm the hostilities.

"The two movements have agreed to call on our Palestinian masses to stop all displays that might lead to tension," Fatah official Maher Mekdad said, reading a joint statement after the meeting. "They agreed to work together to strengthen the national unity."

Outside the meeting, thousands of Fatah supporters shouted anti-Hamas slogans. No agreement was reached in the meeting on the control of the security forces, participants said.

The unrest followed the president's recent moves to take control of all six security forces and Hamas's response that it would form its own shadow army, made up of militants and headed by a top fugitive Israel has been hunting for years.

Abbas' prompt veto of that plan provoked a scathing comment late Friday from ruling Hamas party's political chief, Khaled Mashaal.

"We can understand that Israel and America are persecuting us, and seeking ways to besiege and starve us, but what about the sons of our people who are plotting against us, who are following a studied plan to make us fail," Mashaal said from his base in Syria, without mentioning Abbas by name.