Thirteen people were shot dead on Friday when supporters of the Muslim Brotherhood clashed with police across Egypt, defying a state crackdown on the organisation.
Daily demonstrations have been held since the overthrow of President Mohamed Mursi by the Army on 3 July, even since the government declared the Brotherhood a terrorist group on 25 December.
The government is using the new classification to detain hundreds of Brotherhood supporters.
In the Cairo district of Nasr City, riot police fired teargas at protesters throwing fireworks and stones.
There were a number of other clashes across the country.
Founded in 1928, the Muslim Brotherhood was previously banned in 1954.