Hundreds of activists – largely secular and liberal groups – have marched through central Cairo to commemorate violent clashes in December 2011 in which 17 people died.
The deaths occurred during one of the early crackdowns on continued protests after the uprising that forced leader Hosni Mubarak from power.
Monday’s march defied the recently introduced law banning rallies without prior permission which has caused an outcry from non-Islamist youth groups.
After an hour it turned violent as protesters called for the end to the current military-backed government.
On the political front, some sources claim a group calling itself “The Anti-Coup Alliance” – which includes the Muslim Brotherhood – is to boycott January’s referendum on Egypt’s amended constitution.