Alexandria criminal court has adjourned the retrial of two policemen over the killing of Khaled Said until Wednesday.
Supporters of Said – who was killed in 2010 – scuffled with the defendants' relatives inside the courtroom.
Outside the court, security forces used batons, water cannons and teargas to disperse activists who were chanting against the interior ministry – the body responsible for the police – and police brutality.
Police chased protesters down side streets where the clashes continued. One protester received a head wound in the fighting.
The killing of Khaled Said by police in Alexandria helped trigger the popular uprising that toppled Hosni Mubarak in February 2011.
In October 2012, two policemen were sentenced to seven years in jail for the illegal imprisonment and torture of Said. Both prosecution and defence appealed the original sentence.