Clashes have erupted in Egyptian cities after supporters of ousted President Mohammed Morsi took to the streets.

Heavy gunfire and explosions were heard in the centre of Cairo and tear gas has been used. The government denied reports that a protester was killed.

Troops were out in force to prevent the protesters reaching Tahrir Square.

State TV reported further clashes in the northern Sharqiya district and to the east in Giza, as well as in the northern port city of Alexandria.