Supporters of deposed president Mohamed Morsi protested throughout Egypt on Friday in their biggest demonstrations for two weeks.
The BBC reports six people were killed and dozens injured in clashes with security forces.
Incidents were reported in Alexandria, Port Said and in the Nile Delta town of Zagazig.
In Cairo, the demonstrators avoided the capital's bigger squares.
The Muslim Brotherhood is demanding the reinstatement of Mr Morsi who was deposed by the Army on 3 July, just after the first anniversary of his election last year.