GAZA CITY - Hamas fighters were in full control of the Gaza Strip on Friday after routing their Fatah rivals in days of vicious gunbattles.

The democratically elected group overran the territory hours after president Mahmud Abbas sacked the government and declared a state of emergency in a bid to avert all-out civil war.

Sporadic gunfire rattled across the impoverished strip, now completely sealed off from the outside world by Israel, as looters took to the streets.

Hamas's action, branded a "military coup" by Abbas and triggering alarm among world leaders, splits the Palestinians into two entities and throws into jeopardy any prospect for an independent state and peace with Israel.

Abbas on Friday tasked independent Salam Fayyad with forming an emergency government after dismissing the Hamas-led unity cabinet, an experiment in power-sharing that failed barely three months after it took office.

Hamas snatched the Fatah strongholds one by one on Thursday, hoisting their green flags across Gaza after an explosion of bloodshed that cost at least 113 lives despite desperate efforts to broker a ceasefire.

The international community condemned the seizure and voiced increasing alarm about the humanitarian situation in Gaza, where the clashes have cut power and sent many of the 1.5 million residents cowering inside for days.

Arab foreign ministers were holding emergency talks in Egypt while foreign ministers from the international Middle East Quartet were to discuss the crisis by phone.

Inside the battered jewel of the Fatah crown in Gaza -- Abbas's seafront presidential compound which was the final stronghold to fall in battle -- Hamas fighters seized weapons, computers and documents and cars.

In the West Bank, shops affiliated with Hamas sympathisers were torched in Bethelehem.

The takeover leaves Hamas in charge of Gaza, a tiny overcrowded strip of land bordering Israel and Egypt, while Fatah retains its powerbase in the occupied West Bank.

"We have destroyed the Palestinian cause and the dream of the Palestinian state," lamented Abu Said, 45, from the Shatti refugee camp in Gaza City, home of the sacked Hamas premier Ismail Haniya.

"This is the worst thing I've seen since 1967," chief Palestinian negotiator Saeb Erakat said. "Unfortunately this pushed us back, it pushed us many years back."

On the ground, Hamas released dozens of Palestinian security commanders and Fatah officials detained during its assault, while Egypt recalled all its diplomatic and security personnel from Gaza.

Abbas's announcement ended a fractious power-sharing accord between the two rivals, locked for months in a deadly feud that has seen more than 260 people killed since December.

But Hamas dismissed the declaration as "practically worthless" -- raising the prospect of two rival Palestinian governments.

Hamas's victory in 2006 triggered a crippling Western aid boycott which remains largely in place today, plunging the Palestinians deeper into economic hardship.

The Israeli press was awash with alarmist editorials.

In one of the fiercest clashes on Thursday that left 14 dead, masked Hamas gunmen stormed the preventive security force compound in Gaza City and dragged out Fatah fighters, some stripped to their underwear, their hands in the air.

US Secretary of State Condoleezza Rice called Abbas to voice Washington's "full support" while Russia called on the Palestinians to end a "fratricidal conflict... in which there cannot be a winner."

Britain denounced Hamas, saying "once again extremists carrying guns have prevented progress against the wishes of the majority who seek a peaceful two-state solution."

Human Rights Watch has accused both sides of committing war crimes during the fighting, which has turned hospitals into battlegrounds, seen ambulances prevented from reaching wounded and peace demonstrators shot dead.

UN chief Ban Ki-moon held preliminary talks on the idea of sending an international force to Gaza, but Hamas rejected the move, saying it would treat foreign troops as occupation forces.