Egyptian security forces shot dead at least 70 supporters of ousted President Mohamed Morsi early on Saturday, his Muslim Brotherhood said, deepening the turmoil which has convulsed Egypt for weeks.
Brotherhood spokesman Gehad El-Haddad said the shooting started shortly before pre-dawn morning prayers on the fringes of a round-the-clock vigil being staged by backers of Mohamed Morsi, who was toppled by the army more than three weeks ago.
"They are not shooting to wound, they are shooting to kill," Haddad said, adding that the death toll might be much higher.
Al Jazeera's Egypt television station reported that 120 had been killed and some 4,500 injured in the early morning violence on the fringes of a round-the-clock vigil being staged by backers of Mohamed Morsi near Cairo's Rabaa al-Adawia mosque.
Reporters at the scene said firing could still be heard hours after the troubles started. "I have been trying to make the youth withdraw for five hours. I can't. They are saying have paid with their blood and they do not want to retreat," said Saad el-Hosseini, a senior Brotherhood politician.
"It is a first attempt to clear Rabaa al-Adawia," he added. There was no immediate comment from state authorities on what had happened.
Supporters and opponents of Mohamed Morsi staged mass rival rallies across the country on Friday, bringing hundreds of thousands into the streets and laying bare deep divisions within the Arab world's most populous country.
Well over 200 people have died in violence since the overthrow of Mohamed Morsi, including at least nine on Friday, most of them Brotherhood supporters.
Army chief General Abdel Fattah al-Sisi, who played a central role in the overthrow of Mohamed Morsi following huge demonstrations against his year-long rule, called for Egyptians to rally on Friday to give him a mandate to tackle "violence and terrorism".
Hundreds of thousands heeded his call, but Muslim Brotherhood supporters also staged mass, counter-rallies, demanding the reinstatement of Mohamed Morsi, who was placed under investigation on Friday for a raft of crimes, including murder.
Asked what the strategy of the Brotherhood would be after the second mass killing of its supporters this month by security forces,