A spokeswoman for Arafat denied that the 75-year-old was brain dead but admitted he was comatose and "between life and death".

"He could wake up, but he could not wake up," Laila Shahid, one of handful of people authorised to visit Arafat, told French radio.

The coma was such that Arafat, who has personified the Palestinian fight for a homeland for nearly half a century, could stay in it "a long time" or "come out of it," she said.

French medical sources had said Thursday that Arafat was "brain dead" and only breathing with the help of life support machines at a military hospital in Clamart on the southwestern outskirts of Paris.

It marked a dramatic deterioration for Arafat who was airlifted a week ago out of his West Bank headquarters, where he had been kept under virtual house arrest by Israel for nearly three years.

While insisting that talk of Arafat's permanent demise was premature, Palestinian officials are trying to make sure that his death does not leave a power vacuum or trigger an outbreak of violence in a society where the number of gunmen has mushroomed during the four-year uprising against Israel.

All the branches of the Palestinian security services were placed on maximum alert late Thursday while senior representatives of all the main Palestinian factions were to meet in Gaza City.

Mohammed al-Hindi, the head of Islamic Jihad in Gaza, said the high committee of Palestinian and national Islamic factions -- an umbrella organisation which includes the Islamist movement Hamas and Arafat's Fatah faction -- would meet at the local offices of the Palestinian parliament.

"We will discuss the dangerous situation, especially what will happen if the president were to die," Hindi told AFP. "Inshallah (God willing), we hope he will recover."

Israeli authorities were also trying to keep the lid on the simmering situation, barring any Palestinian man under the age of 50 from entering the country from the occupied territories.

Its security forces operating in Gaza and the West Bank have also been placed on maximum security.

Several hundred Palestinians staged an overnight vigil for Arafat outside his battered Muqataa headquarters in the West Bank town of Ramallah.

Starved of news from the official media, foreign journalists were badgered by Palestinians for information about the state of the man who is the only leader they have ever known.

Israelis were meanwhile trying to absorb the implications of the apparent end of the Arafat era.

Some could barely contain their delight with Hatzofe, the mouthpiece of the Jewish settler movement, running the headline "Arafat Alive -- Until the Current is Shut Off".

Israeli ministers have been trying to avoid commenting on Arafat's condition amid the conflicting reports about his status. Neither do they want to be seen endorsing a potential successor.

However Arafat's death has the potential to galvanise the moribund bilateral peace process, with former Palestinian prime minister Mahmud Abbas emerging as the front runner in the succession race.

Abbas has been acting head of both the Palestine Liberation Organisation and Fatah since Arafat's departure.

While Israeli Prime Minister Ariel Sharon and US President George W. Bush have boycotted Arafat for the last four years, Abbas was a guest of both during his brief premiership last year.

"His dying puts the Israeli government in a number of dilemmas," said an editorial in the top-selling Yediot Aharonot daily.

"Unlike Arafat, Abu Mazen (Abbas) is opposed to terror in every fibre of his being. Unlike him, he made the move from the era of the underground to complete identification with the values of the West.

"In a certain sense, Arafat was a convenient adversary. It was easy to dismiss him, to rip, as (former Israeli premier) Ehud Barak claimed, the mask from his face. It will be more complicated with Abu Mazen."

Bush, buoyed by his solid re-election victory, expressed hope Thursday of making "good progress" in resolving the Israeli-Palestinian conflict in his second term, with analysts expecting the end of Arafat's reign could lead to a greater US role.

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