Egypt unrest: 11 deaths at Muslim Brotherhood protests
Eleven people have died in clashes between police and Muslim Brotherhood demonstrators across Egypt, the health ministry says.
The Muslim Brotherhood put the death toll at 17. Dozens of people, including police, have been wounded.
The deaths were reported in the capital Cairo and the cities of Alexandria, Fayoum and Ismailia.
Authorities have recently intensified a crackdown on the movement, which has been declared a terrorist group.
In Friday's violence, police fought with demonstrators, some throwing stones and fireworks and setting police vehicles on fire, in several districts in the capital.
Authorities said 122 protesters had been arrested.
The health ministry said 52 people had been wounded in the clashes, with several people reported injured by birdshot in Alexandria.
The latest clashes come a day after two people were killed in violence at an Islamist demonstration in the northern coastal city.
Supporters of the Brotherhood's ousted President Mohammed Morsi have held frequent protests since he was removed by the military in July.
The Brotherhood, which had been banned since September from all activity, was declared a terrorist group in December after it was blamed for a suicide bombing of a police headquarters in the Nile Delta.
The Brotherhood denied carrying out the attack. A Sinai-based Salafist-jihadist group, Ansar Bayt al-Maqdis, said it was behind the bombing, which killed at least 15 people.
Mr Morsi's government - the first to be democratically elected in Egypt - was toppled on 3 July following widespread anti-Brotherhood demonstrations.
Since then, thousands of Brotherhood members, including its leadership, had been arrested and many put on trial.
The ousted president is on trial on several charges, including incitement to murder.