Cairo clashes leave 24 dead and more than 200 wounded after Coptic church protest since Egypt's former President Hosni Mubarak was ousted in February.
The attack took place in Aswan province last week with Coptic Christians blaming on Muslim radicals.
Prime Minister ESSAM SHARAF said what was taking place were not clashes between Muslims and Christians but attempts to provoke chaos and dissent.
Funerals are to be held and the cabinet organizes an emergency meeting on Monday.
Thousands joined the march from the Shubra district of northern Cairo to the state TV building in Maspero Square for a sit-in. But the clashes began here and were spread to Tahrir Square, the epicentre of the demonstrations which led to President Mubarak's resignation.
The Copts, the largest minority in Egypt require presidential permission for churches to be built. Egypt only recognizes conversions from Christianity to Islam, not the other way.