The Saturday ruling by the military-installed judiciary is the latest in a string of criminal trials that rights groups say has failed to hold Egyptian security forces responsible for the killing of many protesters.

The acquittals come as ousted President Mohammed Morsi, toppled in July by the military, faces a host of criminal allegations. Morsi appeared in court 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 long-time ruler 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.

None of the police officers charged with killing protesters in 2011 are behind bars, leading 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 Though 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."

RA/MB