Former Egyptian President Hosni Mubarak has been moved from prison to an army hospital in the capital, Cairo, where he remains in a critical condition.
He is said to have had a series of strokes and to be on a life support machine. Reports that he was "clinically dead" were later denied. But there is no official statement.
The reports come amid protests over disputed presidential election results and new powers for the military.
Mubarak, 84, was ousted last year.
On 2 June, he was jailed for life for his role in the deaths of protesters.
There have been frequent reports since then that his health has deteriorated, many of which have proved wrong.
Mubarak's wife, Suzanne, is reported to be at her husband's bedside at the hospital in Maadi, a suburb south of Cairo.
Meanwhile, tens of thousands of people protested in Cairo's Tahrir Square against a move by the Supreme Council of the Armed Forces (Scaf) to assume new powers.
The rally was called by the Muslim Brotherhood, which is also claiming victory for its candidate Mohammed Mursi in last weekend's presidential elections.
His rival Ahmed Shafiq, a former prime minister under Mubarak, has also said he has won.
Results are expected to be announced on Thursday.
The Muslim Brotherhood has also vowed to retry Mubarak once in power, and insists that he should face the death penalty.
As Egyptians voted, the generals dissolved parliament and claimed all legislative power for themselves.
Activists have described the moves as a "military coup".
On Tuesday, Mubarak - who ruled Egypt for 30 years - was transferred by helicopter to intensive care at the armed forces hospital after suffering a stroke, state media said.
Correspondents say the hospital is better equipped to deal with such conditions than the prison hospital where he was being treated.
The former leader is now said to be unconscious and on life support.
Doctors are said to have used a defibrillator on him several times. The device delivers an electric shock to the heart to try to re-establish a normal heartbeat.
Through the night, supporters and opponents gathered outside the Maadi military hospital, where the former president is being treated.
One woman, a supporter, was almost shaking with emotion and saying "I love him".
Another supporter, a man, stood holding a poster of Mubarak. "He is my father. I love him more than my father. The Muslim Brotherhood are criminals. They have destroyed our country. Mubarak kept us in peace for 30 years," he said.
A group of anti-Mubarak young men responded by shouting: "We are poor, and he did nothing for us. His family ate meat and we were starving."
"I'm ready to hammer his grave with my shoe," another protester added.
Egyptians will be very sceptical about any reports about the former president's health, the BBC's Jon Leyne in Cairo says.
Before Mubarak's trial began, his lawyer said he was in a coma, only for the former president to appear - alive and conscious, if not particularly well - in court, our correspondent says.
Now there will be fears that the state of Mubarak's health could be used as a distraction, as Egypt waits for the result of the hotly disputed presidential election.
However, our correspondent adds, the latest reports are better sourced than any before.
In another development on Wednesday, the BBC's Ashraf Madbouli in Cairo reports that tanks and armoured vehicles have been deployed on the Cairo-Alexandria Agricultural Road, just outside the city.
Soldiers refused to answer questions and ordered passers-by not to get too close to the vehicles.
It is the first time the military has been deployed in the area since the downfall of Mubarak last year, our correspondent adds.