Egypt unrest: 'Pools of blood' on Cairo streets
Running battles are continuing on the streets of Cairo.
The Muslim Brotherhood in Egypt says dozens of its supporters were killed overnight in clashes with security forces.
Tens of thousands of supporters of the ousted President Mohamed Morsi have been staging a sit-in at a mosque.
It is not clear whether they were killed when security forces tried to clear the area.
The BBC's Quentin Somerville reports from a makeshift barricade as clashes continue.