An Egyptian court acquitted six police officers Saturday on charges of killing 83 protesters during the country's 2011 revolution – the latest in a string of trials that rights group say failed to hold the country's security forces accountable for demonstrators' deaths.

The acquittals come as ousted Islamist President Mohammed Morsi, toppled in July by the military, also appeared in court to face a number of criminal charges.

Morsi appeared Saturday in a case that charges him and 130 others over prison breaks that freed some 20,000 inmates during the 18-day revolt in 2011 that toppled former leader Hosni Mubarak.

The police officers' case involved the killing of protesters in the Mediterranean city of Alexandria, and included the former head of security and of the riot police.

Prosecutors alleged that commanders armed police with live ammunition and allowed officers to shoot at protesters in front of police stations from nearby rooftops.

Lawyers for the officers denied that they were responsible for the killings. During a Jan. 19 hearing, lawyers referred to Morsi's Muslim Brotherhood group as the "real killers" of the protesters, the state-run daily newspaper Al-Ahram reported.

Given the chaos surrounding the uprising, legal experts say it is difficult to hold any individual legally responsible for a specific killing. But the fact that not even one of the police officers charged with killing protesters in 2011 is behind bars has lead rights groups to accuse Egypt's judiciary of protecting security forces at the expense of justice.

"The consecutive regimes did not have the political will to hold the criminals accountable, allowing them to go away with it," said rights lawyer Ahmed Ezzat, who works with the prominent Freedom of Thought and Expression group.

"These acquittals strengthen (Mubarak's) position. ... Now we have the interim authorities putting it all again on Morsi."

Police brutality during Mubarak's 29 years in office was a key cause of the 2011 uprising.

However, the army and Morsi failed to reform the force. Since Morsi's ouster on July 3, thousands have been killed and injured in heavy security force crackdowns on Morsi's supporters.

"Policemen who are acquitted come out of detention fiercer," Ezzat said. "They will kill more protesters."

Lawyers for the police officers charged could not immediately be reached for comment Saturday.

Meanwhile Saturday, a court sentenced 15 fans of Egypt's Al-Ahly soccer team to two years in prison and fines of 50,000 Egyptian pounds (nearly $7,100) for protesting without a permit in January.

The fans, known as Ultras, were among the youth groups that joined the 2011 uprising against Mubarak and demonstrations against Morsi.

The Associated Press