Ten people were injured in confrontations between supporters and opponents of ousted President Mohamed Mursi in Damietta late on Saturday.
Mursi's supporters had organized a march where they chanted slogans against the army and police that provoked the residents of Damietta City and led to violence, an eyewitness said.
Security forces intervened and dispersed the clashes with water cannons and teargas.
The fronts of several stores and some vehicles were damaged in the clashes.
Security forces said they arrested three people who are supporters of the Muslim Brotherhood from which Mursi hailed.