Egypt's Muslim Brotherhood has called for an uprising against the army, after at least 51 people were shot dead at a demonstration in Cairo.
The army claims it opened fire because "a terrorist group" tried to storm the military compound, where former president Mohamed Morsi is believed to be held.
The Morsi supporters said they were shot during morning prayers.
ITV News' International Correspondent John Irvine reports.
The Muslim Brotherhood tells ITV News they are against violence but will "pay the price of their blood" to restore their ousted president.
Egypt's army has named two further officials in the transitional government as its supporters and opponents vowed to stay on the streets.
There has been outrage in Egypt after 51 people were killed near an barracks where ousted President Mohamed Morsi is thought to be held.