QALQILYA, West Bank: Six people were killed yesterday when forces loyal to Palestinian President Mahmoud Abbas raided a Hamas hide-out just days after he promised in Washington to fulfill his security commitments.

The violence erupted when police encircled a house in the West Bank town of Qalqilya where a top Hamas field commander, Mohammad Samman, and his deputy Mohammad Yasin had taken refuge, witnesses and security officers said. Samman has been on Israel's wanted list.

Both Hamas men and the homeowner died in the shootout, along with three policemen. Dozens of bullet holes in walls and furniture in the home attested to the ferocity of the fighting.

Qalqilya, which elected a Hamas mayor in 2005, was tense. Women gathered near the scene, heaping insults on policemen. Sporadic gunfire erupted in other areas of town and police said the shots came from Hamas loyalists targeting officers. There were no reports of injuries. A curfew was imposed on the town near the border with Israel.

It was the bloodiest internal Palestinian clash in the occupied West Bank since Abbas launched a security drive and revived peace talks with Israel in 2007 after breaking with Hamas over its takeover of the Gaza Strip.

Samman and Yasin ignored calls to surrender, witnesses said. Palestinian security forces spokesman Adnan Damiri said police had tried to negotiate a peaceful end to the standoff. "Thousands of shots were fired at the security forces," Damiri said, adding that large quantities of explosives were found in the Hamas hide-out.

"The Palestinian security forces will strike with an iron fist against anyone harming the interests of the Palestinian people," Abbas, who described the Hamas men as "outlaws," was quoted as saying by the Palestinian WAFA news agency.

Abbas aide Nabil Abu Rudainah said going after militants is key to one day setting up a Palestinian state. "To build our country and our state, we need to have one authority, one gun, one law," he said.

Abu Obeida, a spokesman for Hamas' military wing, threatened "tough and harsh reprisal."

At a news conference in Gaza, a Hamas spokesman described Abbas and his forces as agents of Israel. "There is no difference between the occupation which shoots and the people who carry out their missions for them," he said.

The deep-seated rivalries between Hamas and Fatah boiled over in June 2007 when Hamas violently seized control of Gaza, causing a split in Palestinian ranks that has become a key stumbling block in efforts to reach Middle East peace. Hamas spokesman Fawzi Barhoum said there was no chance of further reconciliation talks with Fatah after the "escalation by security services of Abu Mazen and Fatah against Hamas and its leaders in the West Bank."

"Fatah should choose: Dialogue with us or doing the dirty work of the Zionist enemy," Barhoum said.