RISING TENSIONS
In an early incident that raised tensions in Cairo, three protesters were shot dead outside the Republican Guard barracks where deposed Morsi is being held, security sources said.
The army denied blame for the shootings. An army spokesman said troops did not open fire on the demonstrators and soldiers used blank rounds and teargas to control the crowd.
It was unclear whether security forces units other than army troops were also present.
Later, tens of thousands of cheering Islamists gathered near a mosque in a Cairo suburb where they were addressed by Brotherhood leader Mohamed Badie, free to address them despite reports on Thursday that he had been arrested.
Badie, like some other leaders, pledge that it was worth "our lives" to restore Morsi to the presidency. But Brotherhood officials have also insisted they will not resort to violence.
After dark, running battles broke out in the area between Tahrir Square and the state broadcasting headquarters. Reuters journalists saw hundreds of youths from either side skirmish around the highway ramps of a major bridge over the Nile.
There was some shotgun fire, rocks flew and fireworks shot between rival groups. A car was burned out. Protesters erected makeshift shields for protection. The Brotherhood said 18 of its supporters were wounded after they were attacked by "thugs".
Reuters journalists saw several men with shotgun wounds.
The army, which had pledged to protect demonstrators and keep rival factions apart, had troops in the area but violence only ended after some three hours when half a dozen armoured personnel carriers arrived and took up position on the bridge.
Islamists also took to the streets in cities across the country, including Assiut, Damanhour, Ismailia, and in the Nile Delta towns of Gharbeya and Beheira.