ABASSAN, Gaza Strip (AP)-- Hamas and Fatah gunmen clashed early Monday, leaving at least three Palestinians dead in the most serious fighting between the two powerful factions since Hamas took power.

The rivals are fighting for control of the Palestinian security forces. Fatah, which ruled Palestinian politics for four decades, dominates the forces but increasingly has been unable to keep order, especially since Israel pulled out of the Gaza Strip last summer.

Talks between Palestinian President Mahmoud Abbas and Prime Minister Ismail Haniyeh have failed to resolve the crisis. Abbas, of Fatah, still wields significant authority and has stripped the Hamas government of many of its powers.

The fighting erupted near the city of Khan Younis, apparently during an exchange of captives, the officials said.

Hamas claimed Fatah had shot one of its members, who later died in a hospital. Hamas then shot two Fatah members in the street. Assault rifles, submachine guns and even an anti-tank missile usually reserved for fighting against Israel were fired in the streets of the Abassan farming community.

Hamas and Fatah gunmen have clashed sporadically since Hamas took over the Palestinian government in March following an election victory in January — but Monday's clashes were the most serious.

The government is the biggest employer in the Palestinian territories, and the cash crunch is reverberating throughout the West Bank and Gaza.

Frustrations came to the surface Saturday, when hundreds of Palestinians staged strikes and demonstrations in the West Bank and Gaza to demand payment of the overdue salaries, the first public signs of discontent with Hamas' handling of the international financial squeeze.

While the unrest wasn't widespread, it marked a turning point. The Palestinian public has largely backed Hamas' contention that the crisis is the result of Western hostility and previously heeded calls to remain patient.