Egypt's ex-President Hosni Mubarak was sentenced to life in prison for his role in the killing of protesters during last year's revolution that forced him from power, a verdict that caps a stunning fall from grace for a man who ruled the country as his personal fiefdom for nearly three decades.

The 84-year-old Mubarak, the first Arab leader to be tried in his own country, was ferried by helicopter away from the police academy where the trial was held to the Torah prison in Cairo where his sons and members of his regime have been either serving prison sentences or held pending trials over a variety of corruption charges.

Mubarak ruled with unchecked power for 29 years — an era stained by allegations of widespread corruption, police abuses and a strong grip on power by the ruling party.

The harsh sentence against Mubarak, which can be appealed, appeared aimed at defusing tensions ahead of a divisive runoff presidential race that pits Mubarak's last prime minister against the Muslim Brotherhood's candidate.

Mubarak, wearing sunglasses and lying in a gurney, remained silent inside the defendants' cage, surrounded by his once-powerful sons who appeared nervous and had dark circles under their eyes. His elder son Alaa whispered verses from the Quran.

Lawyers representing families of the slain protesters expressed dismay at the ruling after the judge described the case against Mubarak as weak, lacking material evidence or recordings. They feared that the acquittal of six Interior Ministry officials would be used in the appeal to overturn the ruling.

"This ruling is politicised and will be overturned on appeal," said Hisham Naguib, a lawyer representing families of 23 slain protesters and 36 who were wounded as Egyptian security forces cracked down on mass protests that began by calling for reform but escalated to demand Mubarak step down. He did so on February 11, 2011, ceding power to a military council that itself quickly came under criticism for moving too slowly to transition to civilian rule.

Judge Ahmed Rifaat delivered a strongly worded statement before handing down the sentences. Mubarak, who wore sunglasses and a light brown jacket over his clothes, and his co-defendants were in an iron cage.

Rifaat described Mubarak's era as "30 years of darkness" and "a darkened nightmare" that ended only when Egyptians rose up to demand change.

"They peacefully demanded democracy from rulers who held tight grip on power," the judge said.

Rifaat, who was presiding over his last court session before he retires, said Mubarak and el-Adly did not act to stop the killings during 18-day days of mass protests that were met by a deadly crackdown of security forces on unarmed demonstrators. More than 850 protesters were killed, most shot to death, in Cairo and other major cities.

Mubarak and his two sons — Gamal and Alaa — were acquitted on corruption charges, but the sons still faced a separate trial on charges of insider trading. Ex-interior minister Habib el-Adly also was sentenced to life for the protester killings. Six other security officials were acquitted.

As the news of the sentence initially came through to hundreds of protesters and relatives of victims outside the court compound, jubilation erupted with dozens of anti-Mubarak protesters jumping up and down and waving Egyptian flags and their fists in the air.

Scuffles then between Mubarak supporters and opponents broke out inside and outside the courtroom after the verdict was read, reflecting the deep polarisation of the country after more than a year of turmoil. Helmeted riot police also clashed with protesters.

"The people want to cleanse the judiciary," lawyers chanted inside the courtroom after the verdict. Some raised banners that read, "God's verdict is execution".

Rock throwing and fist fights left at least 20 people injured, and a police official said that four people were arrested. The official spoke on condition of anonymity because he was not authorised to release the information.

Thousands of riot police and policemen riding horses had cordoned off the building to prevent protesters and relatives of those slain during the uprising from getting too close. Hundreds stood outside, waving Egyptian flags and chanting slogans demanding "retribution". Some spread Mubarak's picture on the asphalt and walked over it.

Mubarak's verdict came just days after presidential elections have been boiled down to a June 16-17 contest between Mubarak's last prime minister, one-time protege Ahmed Shafiq, and Mubarak's top foe, a Muslim Brotherhood leader Mohammed Morsi.

- AP