Cameras have been installed on residential and government buildings around Tahrir Square so authorities can "capture images of those troublemakers and protesters who attack security forces," said Interior Ministry spokesman Alaa Mahmoud.

Thus far, authorities have arrested 210 protesters, 85 of whom are charged with destroying public property, thuggery and attacking security forces, the Interior Ministry said, according to state TV. Some 44 of those arrested are juveniles who are now back with their families.

"My worry ... is that the while situation will turn ugly, will turn violent if Morsy doesn't rescind (his) decisions (and) engage in dialogue with the rest of the country," ElBaradei said, adding he had met with Morsy a week ago and felt blindsided by his moves.