An Egyptian court has dismissed a murder charge against Hosni Mubarak over the deaths of protesters during the 2011 uprising, sparking a Cairo demonstration that police dispersed with tear gas.
Mubarak, who ruled for three decades until being driven from office, was also acquitted on Saturday of a corruption charge but will remain in jail on a three-year sentence in a separate graft case.
The ruling enraged the strongman's opponents, with about 1000 converging on a central Cairo square to denounce the government.
Police fired tear gas to disperse them and arrested at least 20.
One person was killed in the clashes between Egyptian police and protesters in central Cairo.
Seven of Mubarak's security commanders, including feared former interior minister Habib al-Adly, were acquitted over the deaths of some of the roughly 800 people killed during the revolt.
Cheers erupted in court and Mubarak's sons Alaa and Gamal kissed his forehead when the judge read the verdict in the retrial as the ex-president, 86, lay in an upright stretcher inside the caged dock.
Corruption charges against the sons were also dropped.
The usually stone-faced Mubarak, wearing his trademark sunglasses, allowed himself a faint smile after the verdict was read.
But relatives of those killed expressed dismay.
More than 1000 protesters gathered at an entrance to Cairo's Tahrir Square - the hub of the revolt - chanting "The people demand the toppling of the regime".
They scattered into side streets when police fired tear gas and used water cannon.
One person was killed in the clashes between Egyptian police and protesters in central Cairo.
An appeals court had overturned an initial life sentence for Mubarak in 2012 on a technicality. Saturday's verdict may also be appealed.
Mubarak, who was transported back to a Cairo military hospital where he is being held, appeared in a wheelchair from a balcony door to wave at several dozen cheering supporters.
"I did nothing wrong at all," he told a private Egyptian broadcaster by telephone.
He also praised his time in office, which was marred by police abuses and corruption, especially the decade before his overthrow.
Apparently referring to economic growth, he said: "The last 10 years showed more results than the 20 years before... and then they turned against us."
