Updated

Hosni Mubarak was sentenced to life in prison Saturday for failing to stop the killing of protesters during the uprising that forced him from power last year. The ousted president and his sons were acquitted, however, of corruption charges in a mixed verdict that swiftly provoked a new wave of anger on Egypt's streets.

Calls have gone out for a massive protest at Tahrir Square, the heart of the uprising, at 5 p.m.

After the sentencing, the 84-year old Mubarak suffered a "health crisis" while on a helicopter flight to a Cairo prison hospital, according to security officials who spoke on condition of anonymity because they were not authorized to speak to the media. One state media report said it was a heart attack, but that could not immediately be confirmed.

The officials said Mubarak cried in protest and resisted leaving the helicopter that took him to a prison hospital for the first time since he was detained in April 2011. Mubarak stayed at a regular hospital in his favorite Red Sea resort of Sharm el-Sheikh from his arrest until his trial began in on Aug. 3. The officials said he insisted on the helicopter that he be flown to the military hospital on the eastern outskirts of Cairo where he has stayed during the trial.

Mubarak finally left the chopper and moved to the Torah prison hospital more than two hours after his helicopter landed there.

Earlier, Mubarak sat stone-faced and frowning in the courtroom's metal defendants' cage while judge Ahmed Rifaat read out the conviction and sentence against him, showing no emotion with his eyes concealed by dark sunglasses. His sons Gamal and Alaa looked nervous but also did not react to either the conviction of their father or their own acquittals.

Mubarak was convicted of complicity in the killing of some 900 protesters during the 18-day uprising that forced him to resign in February 2011. He and his two sons were acquitted of corruption charges, along with a family friend who is on the run.

Rifaat opened the session with a strongly worded statement before handing down the verdicts. He expressed deep sympathy for the uprising.

"The people released a collective sigh of relief after a nightmare that did not, as is customary, last for a night, but for almost 30 black, black, black years -- darkness that resembled a winter night.

"The revolution by the people of Egypt was inspired by God. They did not seek a luxurious life or to sit atop the world, but asked their politicians, rulers and those in authority to give them a decent life and a bite to eat," he said. "They peacefully demanded democracy from rulers who held a tight grip on power."

Angered by the acquittals of the Mubarak sons and six top police officers, lawyers for the victims' families broke out chanting inside the courtroom as soon as Rifaat finished reading the verdict.

"The people want to cleanse the judiciary," they chanted. Some raised banners that read: "God's verdict is execution."

The charges related to killing protesters carried a possible death sentence that the judge chose not to impose, opting instead to send Mubarak to prison for the rest of his life

Rifaat criticized the prosecution's case, saying it lacked concrete and material evidence and that there was nothing in what has been presented to the court that proved that the protesters were killed by the police. Because those who pulled the trigger have not been arrested, he added, he could not convict any of the top police officers of complicity in the killing of the protesters.

The prosecution had complained during the trial that it did not receive any help from the Interior Ministry in its preparation for the case and, in some cases, prosecutors were met with obstruction.

Outside the courtroom on the outskirts of the capital, there was jubilation initially when the conviction was announced, with one man falling to his knees and prostrating himself in prayer on the pavement and others dancing, pumping fists in the air and shooting off fireworks.
  But that scene soon descended into tensions and scuffles, as thousands of riot police in helmets and shields held the restive, mostly anti-Mubarak crowd back behind a cordon protecting the court.

Later, thousands of protesters gathered in Cairo's Tahrir Square, birthplace of the uprising, and in the Mediterranean city of Alexandria on Egypt's northern coast. They chanted slogans denouncing the trial as "theatrical" and against the ruling generals who took over for Mubarak, led by his former defense minister. "Execute them, execute them!" chanted the protesters in Alexandria.

Mubarak and his former Interior Minister Habib el-Adly, who was in charge of the police and other security forces at the time of the uprising, were convicted of failing to act to stop the killings during the opening days of the revolt, when the bulk of protesters died. El-Adly also received a life sentence.

Most of the dead were either shot or run over by police vehicles in Cairo and a string of major cities across the country.

Mubarak and his sons -- one-time heir apparent Gamal and wealthy businessman Alaa -- were acquitted on corruption charges, with the judge citing a 10-year statute of limitations that had lapsed since the alleged crimes were committed.

Just days before the verdict was made public, the state prosecutor leveled new charges of insider trading against the two sons. It now appears that these charges may have been an attempt to head off new public outrage once the acquittals of the Mubarak sons were made public.

It has appeared all along that prosecutions since Mubarak's fall targeting relatively few high level officials and their cronies have been motivated largely by a desire to appease public anger expressed in massive street protests that continued long after Mubarak's ouster.

Scores of policemen charged with killing protesters have either been acquitted or received light sentences, angering relatives of the victims and the pro-democracy youth groups behind the uprising.

Rock-throwing and fist fights outside the courtroom left at least 20 people injured, and a police official said that four people were arrested.

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 Mohammed Morsi of the Muslim Brotherhood, a fundamentalist Islamist group that Mubarak persecuted for most of his years in power.

In a statement posted on his Facebook page, Shafiq said he could not comment on court rulings, but added that the Mubarak trial has shown that no one was above the law in today's Egypt and that no one could recreate the old regime.

The acquittal of the six police officers, he added, did not mean that he approved of their "tactics."

In contrast, a spokesman for Morsi said the verdicts were "shocking" and vowed retribution.

"The blood of our martyrs will not go in vain. We will work as Egyptians for the sake of a just retribution and the retrial of those who committed crimes against this nation," said the spokesman, Ahmed Abdel-Atti.

Morsi and Shafiq will go on a head-to-head presidential runoff on June 16-17.