Egypt: 'This will turn, eventually, in to a civil war'
16 August 2013 Last updated at 19:22 BST
More violence came as thousands of supporters of the ousted President held rallies across the country, in defiance of the military.
The recent protests were over the deaths of 600 people earlier in the week.
Middle East Editor Jeremy Bowen visited a mosque near Ramses Square and he offered his analysis on the current situation in Egypt.