RAMALLAH, Palestinian Territories (AFP) - A Palestinian held by Israel without trial has slipped into a coma after a nearly two-month hunger strike, his lawyer said Friday, raising fears for his life.

"I was informed yesterday (Thursday) evening by the (Israeli) hospital where he is being held that he had fallen into a coma," Jamil al-Khatib, 31-year-old Mohammed Allan's attorney, told AFP.

A spokeswoman for Barzilai hospital in the southern city of Ashkelon confirmed Allan's condition had "deteriorated", adding he was receiving fluids and salts by intravenous drip and aided by an artificial respirator.

"His condition is stable," she said in a statement.

"The treatment is in accordance with the instructions of the ethics committee."

Allan, an alleged Islamic Jihad activist who has been held without charge by Israel since November, has been on hunger strike since June 18, according to the Palestinian Prisoners Club.

His relatives say his fast began in protest at being held under what Israel calls administrative detention, a controversial procedure allowing indefinite detention without charge.

Israeli figures indicate that of the nearly 5,700 Palestinian prisoners currently held by Israel, some 379 are under administrative detention.

His case has become a source of growing concern among the Palestinian public, while Israel faces a dilemma over whether to force-feed the protester.

In the northern West Bank city of Nablus, near his hometown, around 1,000 staged a march for Allan on Friday.

"My son is in a coma. He's my son, but also the son of the entire Palestinian people," Allan's father Nasser Eddine told the crowd.

Hundreds of people also rallied for Allan after Friday weekly prayers at Al-Aqsa mosque in annexed east Jerusalem, waving his portrait in the Old City and chanting against force-feeding.

Portraits of his pale face framed by a dark beard have been circulating on Palestinian social media, including among Israeli Arabs.

The militant Islamic Jihad movement identified Allan as a member, called for a general mobilisation and warned from Gaza that his death would be an "end to the truce" with Israel.

FORCED FEEDING LAST RESORT

Allan's lawyer said Israel intends to force-feed him, a measure likely to further increase Palestinian anger.

The Israeli Medical Association strongly opposes the practice and has said its members will not participate in force-feeding.

An Israeli official speaking on condition of anonymity said force-feeding was a very last resort and required a judge's approval in every case.

"Before forced feeding, there are many, many medical processes," he said.

"They can give him water and other fluids intravenously. There's no need to go straight to forced-feeding."

Allan was transferred earlier this month from Soroka hospital in Beersheva after doctors there objected to carrying out blood tests against his will, Physicians for Human Rights-Israel said at the time.

On Friday, the NGO appealed to Barzilai medical staff.

"Medical ethics requires that his doctors act in accordance to their understanding of the patient's will," it said.

"PHR-Israel hopes and believes that the doctors in Barzilai hospital have acted with respect and in accordance with Allan's will."

The International Committee of the Red Cross, which has visited Allan several times, has warned that he was "at immediate risk" of death.

He has been taking only water throughout his fast and experts say that survival under such conditions is uncertain after two months.

His supporters say his sight and hearing have been badly impaired.

Palestinians in Israeli prisons regularly go on hunger strike in protest at conditions, particularly those who, like Allan, are held in administrative detention.

On July 30, parliament approved a law allowing prisoners on hunger strike facing death to be force fed, sparking criticism from rights groups and doctors.

That vote came two weeks after Israel freed Islamic Jihad member Khader Adnan following a 56-day hunger strike that brought him near death.

Internal Security Minister Gilad Erdan said the law was necessary to prevent "hunger strikes of terrorists in prisons" being used as a means to pressure Israel into releasing them.