Doctors in France were trying to determine Sunday if Yasser Arafat (searchhas a viral infection or some form of cancer after ruling out leukemia as the cause of the Palestinian leader's dramatic deterioration in health, aides said.

Results from additional medical tests on Arafat are due on Wednesday, said his aide, Mohammed Rashid. But Palestinian Cabinet minister Saeb Erekat (search) told Israel's Army Radio on Sunday that Arafat's doctors would be getting results on tests and issuing a medical report in the next 48 hours.

Arafat was rushed Friday from the West Bank to a French military hospital after being ill for two weeks with what was initially described as a bad flu. The Palestinian leader's symptoms included vomiting and diarrhea.

Earlier, a Palestinian official who spoke on condition of anonymity had said there was a strong possibility Arafat was suffering from leukemia. But initial results from a battery of tests uncovered no signs of the malady, Palestinian officials said.

"Arafat does not have leukemia," Rashid said Saturday night. "It's been ruled out."

With leukemia excluded as a diagnosis, doctors were trying to determine whether Arafat was suffering from another form of cancer, a viral infection or some type of poisoning, Palestinian aides said.

Arafat's doctors said Thursday that they had run toxicology tests on the Palestinian leader and turned up no traces of poison.

Rashid, speaking to reporters, said Arafat was eating again Saturday and able to keep food down.

Hours earlier, the Palestinian envoy to France, Leila Shahid, said Arafat had "spent a very good night" and awoke Saturday "in very good humor, rested."

In Arabic, she said other tests also have "not shown any sign of other dangerous disease." But, "there are other possibilities and we are still exploring," she added in English.

In an interview with Palestinian Satellite Channel television, Shahid said Arafat spent half the day undergoing medical treatment and spoke by phone to his daughter in Tunisia.

"So far the test results are good," Shahid said. "The president is relaxing now, and he hopes he will return to take up his responsibilities soon."

In Ramallah, where Palestinian officials put on a show of unity to dispel concerns about possible chaos and infighting in Arafat's absence, the Palestinian foreign minister also said initial test results were encouraging.

"The president is in good health. So far, all the tests have been good and have shown no serious problem," said Nabil Shaath as he entered a meeting of the top committee of the Palestine Liberation Organization.

Arafat, 75, had been sick for two weeks but took a turn for the worse on Wednesday when he collapsed and briefly lost consciousness. Blood tests revealed a low platelet count — a possible symptom of leukemia, other cancers or other maladies. It is also possible that the platelet problem has nothing to do with what is making him sick.

Testing for leukemia usually involves blood smear tests and examination of bone marrow aspirate and of a bone marrow biopsy. Results from the blood tests and the bone marrow aspirate usually are clear within a few hours. However, it takes several days to get results from a biopsy.

One possibility is that a blood smear test revealed no leukemia cells, but doctors are waiting for results of a bone marrow test, which is more likely to show abnormalities.

A blood test may also have shown no sign of leukemia, but evidence of a different, non-cancerous disease.

French physicians gave Arafat a transfusion of platelets — blood components that aid clotting — that helped increase his count, but they did not know whether the improvement was permanent, said a Palestinian official who spoke on condition of anonymity.