Clashes have erupted in Mansoura, the regional capital of Egypt's Daqahliyah governorate, between opponents and supporters of ousted president Mohamed Morsi, leaving dozens injured, Al-Ahram's Arabic-language news website reported.
Security forces reportedly intervened with teargas to separate the rival groups.
Thousands of pro-Morsi demonstrators gathered outside the Mansoura University Stadium on Sunday, where a former MP for the Muslim Brotherhood's Freedom and Justice Party told crowds that they would not move until Morsi was reinstated as president.
Meanwhile, thousands of anti-Morsi demonstrators gathered at Mansoura's Thawra Square, where they chanted against violence and perceived US support for the ousted president and the Muslim Brotherhood.
In Tanta, the capital of Egypt's Gharbiya governorate, meanwhile, clashes also erupted between rival camps. The number of injuries remains unclear.
The death toll from political violence nationwide has reached at least 37 since Friday, with hundreds reportedly injured in clashes.