MercoPress. South Atlantic News Agency

London: Death toll rises above 52

More than 50 people were killed in Thursday's terror attacks in London, Metropolitan Police Commissioner Sir Ian Blair said.

Sir Ian said there was "great difficulty in determining how many fatalities" because of the damage at scenes of the bombs blasts on the rush hour Tube and a bus. He said 13 people had been killed in the Tavistock Place bomb blast.

He revealed that there were 700 casualties, 350 people were taken to hospital, 22 were still in a critical condition and one person died in hospital.

He said the injured included people from Australia, China, Poland, Portugal and Sierra Leone.

The commissioner said the casualty bureau had already received 104,000 calls.

He said there was "absolutely nothing to suggest that this was a suicide bombing attack although nothing at this stage can be ruled out".

He agreed that the attack "bore all the hallmarks" of an al Qaida operation.

Anti-terrorist branch head Andy Hayman said each of the bombs contained less than 10lbs of high explosives and they were probably placed on the floor of the three Tube trains or, in the case of the bus, on the floor or a seat.

Sir Ian said it was open to question whether the terror cell responsible for the attack was still in the UK.

But he added: "We must remain vigilant."