After six days of fighting that have killed over 100 people and ripped apart Palestinians' hopes for a state, President Mahmoud Abbas dismissed the Hamas-led government and declared a state of emergency. He held out the prospect of early elections but it was gun law not the constitution that held sway in Gaza.

Islamist Hamas fighters hunted down key loyalists of the Western-backed Palestinian president in the Gaza Strip on Thursday after seizing most of the final strongholds of his secular Fatah movement in the enclave.

Hamas militants "executed" a top Fatah "collaborator" and paraded his body through the streets and leaders issued a death list of other Fatah supporters. They dismissed the decrees issued in the Fatah-controlled West Bank and said Prime Minister Ismail Haniyeh of Hamas remained in charge in their enclave.

Jubilant young Hamas gunmen hoisted green Islamist flags over captured Fatah buildings and pounded the remaining Fatah bastion, Abbas's own Gaza compound, with heavy weaponry.

The White House accused them of "acts of terror" and U.S. Secretary of State Condoleezza Rice called Abbas to emphasise support for Palestinian "moderates", but admitted that finding troops for any international force for Gaza would be tough.

Israel and its allies contemplated the emergence of an aggressive, Islamist "Hamastan" on its border and a split between Gaza and the larger West Bank, controlled by Fatah.

In the West Bank, Abbas, signed decrees dismissing a three-month-old unity government formed with Hamas and declaring a state of emergency. But violence overtook any legal moves.

At least 29 more people were killed in Gaza, hospital staff said, including 18 Fatah men found in the headquarters of Abbas's Preventive Security force, whose rout early in the day prompted Hamas to declare victory and the "liberation" of Gaza.

In all, at least 110 people have been killed in six days of fighting that many of Gaza's impoverished 1.5 million people saw as a civil war that has left them under religious rulers set on defying a crippling Israeli and Western embargo on the Strip.

The fighting has already halted aid shipments from Israel.

Casualty figures are unclear, as was the fate of Fatah fighters seen led away, bare-chested, after surrendering. There were unconfirmed reports of prisoners being shot.

A Fatah official in Gaza said he had seen eight colleagues gunned down while he escaped death "by a miracle".

Hamas's armed wing issued a statement saying it had "executed" Samih al-Madhoun of Fatah's al-Aqsa Martyears Brigades, a close ally of Abbas's top security aide Mohammad Dahlan.

Fatah officials said Madhoun was alive but his family said he was missing. A senior Hamas source insisted he had been captured and killed. Residents later said they saw Hamas fighters parading Madhoun's body in the street.

Celebration

For Hamas fighters, some in camouflage uniforms, the fall of the security headquarters was a cause for celebration. They fired gunshots in the air to seal their victory and handed out chocolates to local people in the coastal enclave.

"Allahu akbar!" (God is Greatest) one chanted through a megaphone from the roof of the beachfront headquarters of Fatah's intelligence service, captured later in the day.

Others paraded in the streets and showed off weaponry seized from Fatah, whose forces the United States has helped train and arm in a bid to counter the rise of Hamas -- to little effect.

In a statement of victory, Hamas official Sami Abu Zuhri declared in Gaza: "What happened today in the Preventive Security headquarters was the second liberation of the Gaza Strip, this time from the herds of collaborators," the first being Israel's 2005 pullout of troops and Jewish settlers.

Diplomats told Reuters that an aide to Abbas had admitted that hundreds of Fatah's men ran from the battle or ran out of bullets during the fighting. Those in Abbas's own presidential compound in Gaza were among the few still holding out.

The Islamist group said it had also swept control of other Fatah strongholds across Gaza. Pro-Fatah broadcasts went off the air and the Voice of Palestine radio station was set ablaze.

Some Fatah gunmen retaliated against Hamas in the West Bank, shooting and wounding a Hamas man near Ramallah, seizing Hamas supporters in the towns of Jenin and in Nablus, where they also stormed a Hamas office and hurled its computers out the window.

Businesses owned by Hamas supporters were also targeted by angry crowds in the territory occupied by Israel, where some 2.5 million Palestinians live, in the hills around Jerusalem.