Hundreds of political activists belonging to the 6 April Movement, the rebels and the social revolutionary movements demonstrated outside the Cabinet building to commemorate the second anniversary of the Cabinet clashes.
Though the Interior Ministry said the demonstration was authorized, demonstrators sprayed graffiti calling for a boycott of the constitutional referendum.
The Cabinet clashes took place on 16 December 2011 between the army and protesters when security attempted to disperse a sit-in in Tahrir Square, killing more than 40 protesters.
The protests were against the appointment of Kamal al-Ganzouri as prime minister.
A reported 255 people were injured and 4 killed, including prominent Sheikh Emad Effat.
Edited translation from Al-Masry Al-Youm