Yasser Arafat (search) is fighting for his life in a French hospital and has lost consciousness repeatedly in recent hours, Palestinian officials said Thursday.

The officials said they could not immediately confirm reports that the 75-year-old Palestinian leader had lapsed into a coma.

Arafat's condition deteriorated sharply on Wednesday and he was rushed into intensive care at the French military hospital where he has been undergoing treatment for a week.

Earlier, Israeli media, citing Israeli intelligence and Palestinian officials, said Arafat suffered organ failure. The Maariv daily said Arafat's condition was "very critical."

However, Palestinian Cabinet minister Saeb Erekat (search) said reports that Arafat's organs had failed were "unfounded." He described Arafat's condition as "stable and serious" and said that the most recent blood tests and CT scans conducted Wednesday night and Thursday morning were encouraging.

Other Palestinian officials said Arafat's health had deteriorated, but would not provide details. French hospital and military officials declined to comment.

Doctors still don't know the cause of the blood and digestive disorders uncovered over the past few days, the sources said, adding that Arafat was undergoing additional tests.

Israel Radio reported that Mahmoud Abbas (search), No. 2 in the hierarchy of Arafat's Palestine Liberation Organization and his first prime minister, was on his way Thursday morning to Paris to see him.

Arafat's top aides have denied there was any setback and accused Israel of spreading rumors. The report first aired on Israel's Channel Two television.

"These unfounded reports are not coming from French medical teams, these are leaks from the Israeli side," said Mohammed Dahlan, a former Palestinian security chief.

"Leaking such rumors will only complicate things and also complicate the situation within the Palestinian public," he told reporters in Paris.

Arafat, who has been ill for three weeks, was flown to the French military hospital on Friday after passing out briefly at his west Bank headquarters.

He was initially described as having a bad flu, with symptoms of vomiting and diarrhea.

Palestinian officials insist publicly leukemia and other forms of cancer, as well as any type of poisoning, have been ruled out.

Undoubtedly conscious of the anxiety back home at the thought of a future without Arafat — who has led the Palestinians for 40 years with no obvious successor — they have previously described his condition as improving and said more tests were being done.

Khaled Salem, Arafat's top aide, said early Thursday that the medical analysis was "deepening a little bit" but he remained confident Arafat would recover.

"There are no setbacks," he told reporters outside the hospital. "It's no secret he's ill, that's why he's in France, but there is no threat, there is no danger, no serious degradation."

However, top Israeli security officials were meeting Thursday to study the repercussions in the Middle East should Arafat die, said Israeli officials speaking on condition of anonymity.

Attending the meeting are Defense Minister Shaul Mofaz and Army Chief Lt. Gen. Moshe Yaalon, the officials said.

Speculation in Israel has ranged from a viral infection to stomach cancer.

His brother, Fathi Arafat, has had stomach cancer for four years and is currently hospitalized in Cairo, Egypt, with an advanced stage, according to doctors there.

On Wednesday, Leila Shahid, the Palestinian envoy to France who has been serving as Arafat's official spokeswoman in Paris, said Arafat felt well enough to ask about the U.S. presidential election. An aide later issued a statement in Arafat's name congratulating President Bush on his re-election.