Clashes have erupted in the Egyptian capital between supporters of President Hosni Mubarak and demonstrators calling on him to step down immediately.
Rival groups of protesters are fighting pitched battles in and around Cairo's Tahrir Square. Many people have been wounded and shots have been heard.
Earlier, the army urged people to return home after nine days of anti-government demonstrations.
Mr Mubarak has pledged he will not stand for re-election in September.
On Tuesday, hundreds of thousands had protested across the country against Mr Mubarak, the culmination of more than a week of demonstrations that have left about 300 people dead according to UN estimates.