At least 32 people were killed on Saturday when Egyptians rampaged in protest at the sentencing of 21 people to death over a soccer stadium disaster, violence that compounds a political crisis facing Islamist President Mohamed Mursi.

Two policemen were shot dead outside a prison in Egypt's Port Said on Saturday shortly after a court sentenced to death 21 people found guilty of involvement in Port Said stadium disaster that killed 74 people,  a security source reported.

Protesters had gathered at the prison where many of the defendants in the soccer case were held and state media had earlier reported gunshots outside the jail. State television had earlier reported the sound of gunshots and said police fired tear gas in the area.

The Port Said soccer stadium ruling could help reduce prospects of fresh clashes on Egypt's turbulent streets. Soccer fans and families of those killed had threatened more violence if the punishments did not satisfy them, and many had demanded the accused be executed.

The ruling followed nine deaths during protests nationwide on Friday and early on Saturday, held to mark two years since Egypt's revolution forced strongman Hosni Mubarak from power and to accuse President Mohamed Mursi and his Islamist allies of reimposing authoritarian rule.

The judge, Sobhy Abdel Maguid, read out a list of 21 names "referred to the Mufti", a phrase used to denote a death verdict as all such sentences must be reviewed by Egypt's top religious authority.

Seventy-three people have been charged with involvement in the February 1, 2012 disaster at the end of a match between Cairo's Al Ahly and al-Masry, the local side.

Spectators were crushed when panicked crowds tried to escape from the stadium after a post-match pitch invasion by supporters of al-Masry. Others fell or were thrown from terraces, witnesses said.

Many of those who died were supporters of Al Ahly. The verdicts for others accused will be announced on March 9, said the judge, who had called for calm in the court before and during the reading of the ruling.

In response to the sentences, supporters gathered at Al Ahly club in Cairo cheered. In the courtroom on the outskirts of Cairo, familes of victims clapped and some wept with emotion.

"God is greatest" one shouted, while others held up pictures of the victims.-Reuters