The death toll in pro-democracy protests in Egypt on Sunday climbed to 11, security sources said.
Tight security in Cairo and other cities failed to contain protests marking the anniversary of the 2011 uprising that toppled autocrat Hosny Mubarak.
Security forces have been stamping out dissent in Egypt since then-army chief Abdel Fattah al-Sisi ousted elected President Mohamed Morsy of the Muslim Brotherhood in July 2013 after mass protests against his rule.
Supporters of deposed President Mohamed Morsy of the Muslim Brotherhood gathered near Tahrir Square -- symbolic heart of the 2011 revolt - and held up photographs of him, a witness said. Security forces rounded them up. They also used teargas to disperse a protest in Cairo's Ramses Square, officials said.
Tensions have been rising in Egypt. A woman protester was shot dead on Saturday near Cairo's Tahrir Square, the symbolic heart of the revolt that ended Mubarak's three decades in power. Dozens of protesters were killed during last year's anniversary.
On Friday, a 17-year-old woman was killed during protests in Alexandria. The Muslim Brotherhood accused security forces of shooting her. Her uncle said she had not been protesting but had gone to a store when she was shot.
State news agency MENA said 22 armoured vehicles were parked around Tahrir Square and roads to it were sealed off on Sunday.
Security forces were also dispatched to Rabaa Square in northeast Cairo, where hundreds of Morsy supporters were killed in August 2013 at a protest camp.
A security crackdown has largely ended Egyptian street demonstrations, but several have taken place in the past week in Cairo and Alexandria.
In a televised address on Saturday, President Sisi praised the desire for change that Egyptians showed four years ago but said it would take patience to achieve all of "the revolution's goals".
