Meanwhile, the police station in Al-Zawaida, a village near Deir al-Balah, was burned to the ground by unidentified attackers. There were no reports of casualties and no immediate claim of responsibility.

And Israeli troops destroyed six Palestinian homes in the Rafah refugee camp, in southern Gaza, Palestinian security sources said, recalling a massive demolition operation that sparked international outrage.

A militant of the Al-Aqsa Martyrs Brigade told AFP by telephone from the governor's office that the gunmen were demanding that Musa Arafat go and the reinstatement of more than 50 security officers.

The Brigades, an armed offshoot of Arafat's Fatah group, has led violent protests in Gaza for the past two weeks against Arafat's appointment of Musa, accused of being corrupt, as the territory's security chief.

Witnesses earlier said some 20 armed and masked men forced everyone out of the governor's office in the early morning and took over the building.

Palestinian security sources said the gunmen ended their five-hour siege at about noon (0900 GMT) after an agreement was reached for the security officers to return to work.

Earlier, the Brigades militant, who identified himself as Abu Ahmed, listed their demands as "the reforms demanded by the Palestinian people, corrupt officials be fired and the nomination of Musa Arafat to be cancelled.

The unrest, which has since spread to the West Bank, prompted Palestinian premier Ahmed Qorei to submit his resignation last Saturday.

Arafat has refused to accept Qorei's departure and has called for a radical cabinet reshuffle to confront the crisis.

Palestinian negotiations minister Saeb Erakat warned Friday the Palestinian territories were sliding into "chaos."

On the diplomatic front, it was also announced Friday that US Secretary of State Colin Powell will tour the Middle East next week for discussions on the moribund Middle East peace process and Iraq.

"In the Middle East, Secretary Powell will discuss with our close friends there the situation in Iraq, cooperation in the war on terror, the situation between the Israelis and Palestinians, and the opportunities created by the Gaza withdrawal, and the issue of reform in the broader Middle East and North Africa," spokesman Richard Boucher said.