Egypt: 'Constant wail of ambulance sirens at Tahrir Sq'

With tens of thousands of protesters massing in the centre of Cairo, Egypt's ruling military council has accepted the resignation of the government and promised to bring presidential elections forward.

The BBC's Lyse Doucet in Tahrir Square said there has been a "constant wail of ambulance sirens, a measure of how many people are being injured in these running battles".