Young men threw rocks at police, who responded with tear gas. Two trucks that transport riot police was set ablaze.
Judge Mohammed Hammad Abdel-Hadi resigned from the case on Sunday, giving no reason. His resignation means a new trial for the officers accused of using excessive force.
Since President Hosni Mubarak was deposed in February, almost 100 police officers have been brought to trial on charges of killing and wounding protesters. All were acquitted or received suspended sentences.
Almost weeks of street fighting on downtown Cairo's Mohammed Mahmoud Street in November 2011 killed 42 people, most of them slain by security forces. The demonstrators were demanding a timetable for a military Supreme Council to hand over power and hold Presidential elections.
1425 GMT:Algeria. Seven foreign hostages have reportedly been killed in the final operation by Algerian forces against the kidnappers, 11 of whom were slain.
1340 GMT:Algeria. Algerian State media is reporting that the hostage crisis is over at the In Amenas gas plant, with 11 attackers killed by Algerian forces.
The reports claims that 16 foreign hostages --- including two Americans, two German, and a Portuguese ---- have been freed.
There were so many deaths. I was shocked. I can't say the exact number. Foreign hostages died, Algerian hostages died and there were deaths among the terrorists.
The hostage said one of the leaders of the assailants was killed. Some of the attackers are still in the central working area of the gas facility. People from the area warned, "It's very difficult for the army to stage an assault because everything could explode. It's dangerous."