0947The blast tore through a double-decker bus at the junction of Tavistock Square and Upper Woburn place.
Thirteen people died in the explosion.
One eyewitness said: "It was a massive explosion and there were papers and half a bus flying through the air", said another.
The explosion happened outside the British Medical Association and doctors rushed from the building to perform triage and emergency care to those injured.
The bus was a
number 30, travelling from Marble Arch to Hackney. It was following a diversion from its normal route.
Police said the device could have been placed on a seat or the floor. They later established that it was detonated by suicide bomber Hasib Hussain.