UPDATED 5:21 a.m. Wednesday

CAIRO, Egypt — Egypt’s Hosni Mubarak was being kept alive by life-support Tuesday after he was rushed from prison to a military hospital in a rapidly worsening condition, officials said.

The 84-year-old ousted leader’s health crisis added a new element of uncertainty just as a poten­tially explosive fight opened over who will succeed him.

The state news agency MENA said Mubarak was “clinically dead" when he arrived at the hospital and that doctors used a defibrillator on him several times. It initially said the efforts were not successful.

But the official said Mubarak was put on life-support. He had no further details on his condi­tion.

The official spoke on condition of anonymity because he was not authorized to talk to reporters.

The developments add further layers to what is threatening to become a new chapter of unrest and political power struggles in Egypt, 16 months after Mubarak was ousted by a popular uprising demanding democracy. Egyptians were uncertain about Mubarak’s fate, about who will succeed him and about whether his successor will have any power.

The campaign of Mubarak’s former prime minister, Ahmed Shafiq, said Tuesday he has won Egypt’s presidential election, countering the Muslim Brother­hood’s claim of victory for its candidate, Mohammed Morsi.

The election commission is to announce the official final results on Thursday and no matter who it names as victor, his rival is likely to reject the result as a fraud. If Shafiq in particular is declared the winner, it could spark an explosive backlash from the Brotherhood.

The Brotherhood, Egypt’s most powerful political group, is al­ready escalating its challenge against the ruling military over the generals’ move this week to give themselves overwhelming authority over the next president.

Some 50,000 protesters, mostly Islamists, massed in Cairo’s Tahrir Square on Tuesday evening chanting slogans in support of Morsi and denouncing the gener­als’ power grab.

The health crisis of Mubarak, who is serving a life prison sen­tence, is yet one more thing to stoke the heat.

Moving Mubarak out of prison is likely to further infuriate many in the public. Many Egyptians have been skeptical of earlier reports that his health was worsening since he was put in prison on June 2, believing the reports were just a pretext to move him to another facility.

There is a widespread suspicion that security and military officials sympathetic to their old boss are giving him preferential treatment. Details of the crisis were still sketchy. Earlier, the news agency and officials said that while at the Torah Prison hospital he suffered a “fast deterioration of his health." His heart stopped beating until he was revived by defibrilla­tion, then he suffered a stroke.

At that point, he was moved from the prison hospital to Maadi military hospital — notably the same one where his predecessor Anwar Sadat was declared dead more than 30 years ago after being gunned down by Islamic militants. That was when MENA reported him “clinically dead."

The criteria for using that term are “poorly defined," said Dr. Lance Becker, a University of Pennsylvania emergency medi­cine specialist and an American Heart Association spokesman. “In its crudest form, clinical death just means that a doctor thinks he’s dead — somebody standing at the bedside believes he is dead," he said.

Mubarak’s condition brought to mind former Israeli prime minister Ariel Sharon — though it was not known if there was any medical similarity in their condi­tions. Sharon suffered a massive stroke in 2006. Intensive treat­ment and repeated operations by a team of brain surgeons stabilized his condition, but he never regained consciousness.

Sharon, 84, is still alive but re­mains on life-support in a deep coma.