Egyptian security forces have begun clearing two protest camps in Cairo occupied by supporters of deposed President Mohammed Morsi.
Reports say 15 people have been killed as police cut off side streets and bursts of gunfire were heard.
Teargas is being fired and helicopters flew overhead as security forces moved on the camps in the east and west of the city.
The protesters want Mr Morsi, deposed by the military on 3 July, reinstated.
The interior ministry issued a statement saying security forces were taking “necessary measures” against the protest at the Rabaa al-Adawiya mosque in the east of Cairo and the protest in Nahda Square in the east.
The statement said a safe exit would be provided for protesters and they would not be pursued, “except those who are wanted by the prosecution”.
The interior ministry is keen “not to shed any Egyptian blood”, the statement went on.
Muslim Brotherhood TV, which is allied to the ousted president, called for people to send cars to the sit-ins to take casualties to hospital.
Protesters have been camped outside the mosque, and at Nahda Square for the past six weeks.
More than 250 people have been killed in clashes since then.
On Tuesday, one person was killed in a confrontation between supporters and opponents of Mr Morsi in Giza after people marched from Nahda Square to a nearby complex of government buildings to protest against the appointment of several military officers as provincial governors.
Agencies