Egyptian security forces carried out widespread arrests of Muslim Brotherhood members just days after the government labeled the group, which supports ousted President Mohammed Morsi, a terrorist organization.
Three people were reported killed in Muslim Brotherhood-led protests and some 265 people were arrested as part of the nationwide crackdown, which came as the political group renewed calls for massive anti-government rallies.
"As Friday prayers ended, riot police tried to stop Mr Morsi's supporters holding protest rallies.
"A man was killed in clashes in the city of Samalut in Minya, while an 18-year-old Muslim Brotherhood supporter was shot dead amid violent confrontations in the Nile Delta city of Damietta, police said.
"The interior ministry said a third person was killed in Cairo, without giving further details."
Police fired tear gas in various parts of the capital, and Interior Ministry officials said several security forces personnel were hurt in clashes with protesters.
The Associated Press says:
"In Cairo, riot police chased student protesters chanting against the military and the police at the Islamic Al-Azhar University. Footage on private TV networks showed demonstrators hurling stones and setting fire on tree branches to defuse tear gas smoke. ...
"Clashes also erupted Friday in several other districts of the capital. Al-Jazeera Mubashir Misr TV showed footage of police vehicle on fire in a highway linking Cairo with Giza."