Twenty-one people were injured in Beheira's Damanhour when the city's residents clashed with supporters of former president Mohamed Morsi on Friday noon.
Three of those injured were shot with live ammunition.
Around five thousand pro-Morsi demonstrators were marching from al-Hedaya Mosque when some residents attacked them, an Aswat Masriya eyewitness reported.
The police dispersed the crowds with teargas.
In Kafr al-Dawwar city, hundreds staged a demonstration to declare their support for what they called Morsi's legitimacy.