Anti-government protests have broken out in Egypt after an internet campaign inspired by the uprising in Tunisia.
Thousands of protesters are marching through Cairo chanting anti-government slogans, after activists called for a “day of revolt” in a web message.
Riot police have tackled protesters in the capital, using tear gas to try to disperse them.
Weeks of unrest in Tunisia eventually toppled President Zine al-Abidine Ben Ali earlier this month.
Protests are rare in Egypt, which President Hosni Mubarak has ruled since 1981, tolerating little dissent.
The events in Cairo were co-ordinated on a Facebook page – tens of thousands of supporters clicked on the page to say they would take part.
The BBC’s Jon Leyne in Cairo says rallies are being held in several parts of the capital, and the turnout so far is more than the organisers could have hoped.
He says there has been a series of violent confrontations, including in front of the parliament building, where police with riot shields, tear gas and water cannon clashed with protesters throwing rocks.