The Egyptian government says four people have been killed in clashes amid demonstrations on the third anniversary of the country’s uprising against the Mubarak dictatorship.
Security forces fired into the air in Cairo to disperse anti-government protesters as thousands rallied in support of the army-led authorities.
Witnesses said police also fired tear gas and birdshot at demonstrators near Tahrir Square.
A number of people were arrested. The protesters included supporters of the banned Muslim Brotherhood and also secular people.
Early on Saturday a bomb exploded near a Cairo police academy. The interior ministry said no-one was hurt.
A group inspired by al Qaeda has claimed responsibility for four bomb attacks on Friday that killed six people.
The day also claimed another 15 victims amid demonstrations in favour of deposed President Mohamed Mursi.
Amid tight security ahead of anticipated rallies from rival groups, reports said five soldiers had been killed in a helicopter crash as they tackled Islamist insurgents in the Sinai peninsula.
Instead of commemorating Mubarak’s overthrow, the Tahrir Square demonstration became a show of support for Egypt’s army chief General Abdel Fatah al-Sisi, who toppled Mursi following mass protests against his rule last year.