Egyptian security forces clashed with young men in central Cairo after a protest by several thousand opponents of President Mohamed Mursi, state news agency MENA reported.
The forces fired tear gas at the youths throwing firebombs and stones at them. Police arrested a number of men, MENA reported.
The Friday protest billed as a major demonstration against Mursi drew only a few thousand people, signalling how momentum for protests that erupted around the second anniversary of the uprising that ousted Hosni Mubarak has steadily evaporated.
Members of "rebellion," an anti-Mursi campaign launched this month, gathered signatures at the demonstration for a petition calling for Mursi's removal and early elections.
Organizers said they have collected 2 million signatures.
Mursi presides over a deeply polarized political landscape and a public suffering from the economic impacts of two years of political turmoil since the 2011 uprising.