'Friday of rage' expected on Egypt's streets
Egyptian security forces are on high alert, with thousands of people expected to join anti-government rallies after Friday prayers.
The outlawed opposition group, the Muslim Brotherhood, has called for a "day of rage".
The BBC's Lyse Doucet in Cairo said web access was disrupted and mobile networks were expected to be switched off.
This video footage posted on social media websites purports to show clashes between protesters and police in Suez on Thursday.