At least 15 people are dead in Cairo, according to Reuters, following clashes Sunday between police and Islamist protesters, marking the fourth anniversary of the uprising that ousted then-President Hosni Mubarak.

The AP said 13 more people were injured in clashes in the Matariyah area of the capital.

Al-Ahram reported that police shot dead an armed pro-Muslim Brotherhood protester in the coastal governorate of Alexandria.

The man had been shooting randomly with a automatic rifle at people while marching with a number of pro-Muslim Brotherhood supporters in Alexandria’s Al-Awayed district, according to an interior ministry statement.

Police reportedly arrested another man with an automatic rifle, also in the march, along with two men who held firebombs.

On Friday, 17-year-old pro-Brotherhood protester Sondos Reda Abo Bakr was shot dead with birdshot, in clashes between police and protesters.

On Saturday, Shaimaa El-Sabagh, 33, who took part in a small-scale march organized by the Socialist Popular Alliance Party to commemorate the uprising, was shot dead with birdshot near Talaat Harb Square in downtown Cairo on Saturday. Police denied gunning her down.

Egypt called off official celebrations of the anniversary of the January uprising this year, as it mourns the death of Saudi Arabia’s King Abdullah.