Violence erupted across London for a third night Photos from around the world on 8 August Tottenham after a protest led to riots Images of rioting in Tottenham, north London Photographs from this week's news Photos from around the world on 4 August Readers' photos on the theme power Africa exhibition at the Tate Modern Pictures from the Belfast Photographic Festival Figurative sculptor Sean Henry exhibition

Calling in the army to help quell the looting and disorder in Britain would be a last resort, experts have said. There would be political and practical difficulties, said Dominic Bryan, director of the Institute of Irish Studies at Queen's University, Belfast, a city that saw troops on the streets for decades.

Parliament is being recalled on Thursday in response to rioting in England, the Prime Minister has said. The government's emergency committee Cobra met on Tuesday after rioting spread across London, with violence flaring in other major cities. "We will do everything necessary to restore order to Britain's streets and make them safe for the law-abiding," the PM said outside Downing Street.

Martin Rowson on the Tottenham riot What began as a gathering of around 200 protesters culminated in a full-scale riot spread across north-London suburbs (1min 5sec) Violence on the streets of Tottenham - video Exclusive: Footage from the riots overnight in north London shows the police trying to contain the mayhem on Tottenham High Road