Egypt was bracing for large rallies on Friday after a number of political parties and groups called for anti-government protests.
Protesters are expected to march to central Cairo's Tahrir Square and the presidential palace in the north-eastern area of Heliopolis.
The protesters are also gathering to denounce a call by ultra-conservative cleric Mahmoud Shaaban to kill opposition leaders.
Shaaban's edict raised fears of political violence in Egypt after Tunisia's prominent opposition leader Chokri Belaid was shot dead on Wednesday.
Recent mass rallies in Egyptian provinces have turned violent, resulting in the deaths of dozens over the last month. -