Hosni Mubarak, toppled by an uprising last year after 30 years ruling Egypt, was sentenced to life in jail on Saturday for his role in killing protesters after a trial that sets a precedent for holding Middle East autocrats to account.

But it was not enough for thousands of Egyptians who poured onto the streets after the verdict. Some wanted Mubarak executed, others feared the judge's ruling exposed weaknesses in the case that could let the former military man off on appeal.

Protesters gathered in Cairo's Tahrir Square, the focus for the uprising that drove Mubarak from office on February 11, 2011. Others in the second city of Alexandria chanted: 'We are done with talk, we want an execution!'

The ruling came at a politically fraught time for Egypt, two weeks before a run-off in its first free presidential election that will pit the Muslim Brotherhood, which was banned under Mubarak, against the deposed autocrat's last prime minister.

After a silence during sentencing, scuffles broke out inside the court between security officers and people chanting 'void, void' and 'The people want the cleansing of the judiciary.'

Rather than a healing experience that many Egyptians hoped for, many see the trial that acquitted top security officials showing how much of Mubarak's old order was still in place. Islamists and others called for street protests on Saturday.

It was the first time an ousted Arab leader had faced an ordinary court in person since a wave of uprisings shook the Arab world last year, sweeping away four entrenched rulers.

But the Muslim Brotherhood demanded a re-trial for Mubarak, who made Egypt into a staunch Arab ally of the US.

'The public prosecutor did not carry out its full duty in gathering adequate evidence to convict the accused for killing protesters,' said Yasser Ali, campaign spokesman for Brotherhood presidential candidate Mohamed Mursi.

Mursi has vowed that if he is president, he would use the courts to ensure his predecessor stayed in jail. 'It is not possible to release Mubarak,' he told Reuters on Thursday. 'I promise the martyrs, we will retrieve their rights in full, God willing.'

About 850 people were killed during the 18-day street revolt that toppled Mubarak.

Ahmed Shafiq, Mubarak's last prime minister, an ex-air force chief like his old boss and Mursi's opponent in the presidential run-off, calls Mubarak a role model. He said on his Facebook page that the trial showed no one was above the law.

Mubarak's lawyers have not said if he will appeal.

State television and a source said Mubarak, 84, suffered a 'health crisis' when he was taken by helicopter to a prison on Cairo's outskirts to serve his sentence, causing a delay in transferring him to the facility.

A helicopter had flown Mubarak to the court set up in a police academy on the outskirts of Cairo from the luxurious military-run hospital where he was kept in custody during the 10-month-long trial.

Mubarak was wheeled into a courtroom cage to join co-defendants including his two sons Alaa and Gamal, former Interior Minister Habib al-Adli and six security officials.

Propped up on a hospital stretcher and wearing sunglasses, Mubarak heard the verdict stony-faced. He was acquitted on a separate corruption charge.

Judge Ahmed Refaat sentenced Adli to life in prison but acquitted the senior security officials for lack of evidence.

He quashed charges against Mubarak's sons, relating to abuse of power and graft, but a new case brought against them this week for stock market fraud will keep them behind bars for now.

'The court has ordered a punishment for Hosni Mubarak of life in prison based on charges of participating in crimes of killing and attempted killing,' Refaat told a hushed courtroom.

Outside, Soha Saeed, the wife of one of those killed during the anti-Mubarak revolt, shouted: 'I'm so happy, I'm so happy.' But, as the details of the verdict sunk in, protesters clashed with police, hurling stones and criticising the court.

Despite Mubarak's life sentence, lawyers acting for the families of victims in the uprising said the acquittal of the six security officials showed the weakness of the prosecution case and suggested the jailed president could win an appeal.

Charges against the six included complicity in killing protesters and failing to prevent damage to public property.

'Regarding accusations against the police leadership, the court is of the opinion that none of the actors who committed the crimes of murder were caught during or after the events, so there is no direct evidence for the charges,' the judge said.

'The landmark conviction of ... Mubarak ... sends a powerful message to Egypt's future leaders that they are not above the law,' New York-based Human Rights Watch said on Saturday.

'However, the acquittal of four assistant ministers of interior on the grounds of insufficient evidence highlights the failure of the prosecution to fully investigate responsibility for the shooting of protesters in January 2011, giving a green light to future police abuse,' it said in a statement.

The lawyers for the victims' families said the verdicts against Mubarak and Adli were designed to appease public anger while leaving room for them to be overturned on appeal.

Refaat opened Saturday's proceedings by hailing Egyptians for removing the only leader many of them had known.

'The people of Egypt woke on Tuesday, Jan. 25, 2011, to a new dawn, hoping that they would be able to breathe fresh air ... after 30 years of deep, deep, deep darkness,' he said.

Yet many Egyptians are still waiting for the light - the messy trial and its aftermath typifying the chaos and confusion that have marked a political transition led by the military.

The ruling army council that took over when Mubarak quit has promised to hand over to a freely elected president by July 1.

But many Egyptians are fuming that the pillars of Mubarak's authoritarian rule, including the hated police force, have survived his downfall intact.

'Enough talk, we want execution!' protesters chanted outside the court, which was surrounded by police with riot shields and batons, before the verdict.

Few Egyptians had expected Mubarak to be put to death, although protesters have often hung his effigy from lamp posts.

Hanafi el-Sayed, whose 27-year-old son was killed early in the uprising, travelled from Alexandria for the trial.

'I want nothing less than the death penalty for Mubarak. Anything less and we will not be silent and the revolution will break out again,' he said shortly before the verdict.

State television said the prosecutor-general had ordered that Mubarak be transferred to prison to serve his sentence.

Mubarak routinely appeared in court on a stretcher, but it is not clear what ailed him. He had occupied a large hospital suite and was free to see relatives, walk in the garden and exercise, news reports and a hospital source said this week.-Reuters