A fresh wave of mass protests could leave Egypt teetering on the brink of revolution on Friday after police warned the president they could soon lose control of the demonstrators demanding his overthrow.
Hosni Mubarak's grip on power was slipping on Thursday and momentum appeared to be shifting rapidly in favour of pro-democracy activists.
Undeterred by a violent police response and the deaths of at least seven people after three days of clashes in Cairo and other cities, organisers said they planned to make today's marches the biggest yet. Yesterday police shot dead a protester in north Sinai.
They were given a further boost after Mohamed ElBaradei, one of Mr Mubarak's fiercest critics, returned to Egypt from Vienna to join the protests, providing opponents of the regime with a potential figurehead to rally around.
There are also reports of arrests of opposition figures overnight.
The reported crackdown on the largest opposition movement, the Muslim Brotherhood, came after it said it would back the Friday protests.