At least 15 people have been killed as police moved in to disperse two huge protest camps set up in Cairo by supporters of Egypt's ousted president, Mohamed Morsi.
The interior ministry said two Egypt security force members have been killed at the demonstrations.
An AFP correspondent who counted the bodies at a makeshift morgue at the Raaa al-Adawiya camp said many appeared to have died from gunshot wounds.
Egyptian security forces, backed by armoured cars and bulldozers, moved on Wednesday to clear the camps, showering protesters with tear gas, state television and security officials said.
An Associated Press television video journalist at the scene of the larger of the two camps said he could hear the screams of women as a cloud of white smoke hung over the site in the eastern Cairo suburb of Nasr City.
He said an army bulldozer was removing mounds of sandbags and brick walls built by the protesters as a defence line in the Nasr City camp. Army troops, however, were not taking part in the operation.
The simultaneous actions by the Egyptian forces - at the pro-Morsi encampment in Nasr City and at the site outside the main campus of Cairo University in Giza - began around 7am (1500 AEST).
The pan-Arab Al-Arabiya TV showed images of collapsed tents and burning tyres at the Nasr City protest site. Ambulances were also seen at the scene, as well as some protesters being arrested and led away by the troops.
The Anti-Coup Alliance, an umbrella of pro-Morsi supporters, said in a statement dozens had been killed and injured so far in Wednesday's attacks.
Egypt's interior ministry warned Islamists not to use women and children as human shields during the police operation, a statement on its website said.
Streets around the two main areas were blocked, said local residents.
The military-backed government described the protest camps as violent and unlawful.
