A supporter of Egypt's ousted President Mohammed Morsi holds bricks during clashes on the Al-Malek Al-Saleh bridge in Cairo.
An Egyptian Health Ministry official says four people have been killed in clashes between Islamist supporters of the ousted president and security forces.
Khaled el-Khatib says the four were killed on Friday in Cairo, while 40 others were wounded nationwide.
Fighting broke out when Morsi's supporters tried to converge on Cairo's Tahrir Square.