In pictures: London blasts

1 of 12 At least 37 people have been killed and hundreds more injured in four bomb blasts on the Underground network and a double-decker bus in London. Here emergency services cordon off King's Cross station.

2 of 12 Passengers on the underground begin to evacuate. The lucky ones are in a station...

3 of 12 ...others like Alexander Chadwick near Kings Cross have to walk through the tunnels to safety.

4 of 12 At Aldgate, fire crews bring the injured up from the underground network...

5 of 12 ...but many are left dazed and shocked.

6 of 12 In Tavistock Square, eyewitness Belinda Seabrook described an explosion rip through the bus.. (Photo: Toby Mason).

7 of 12 "I was on the bus in front and heard an incredible bang, I turned round and half the double-decker bus was in the air," she said. (Photo by Mike Hughes)

8 of 12 At Edgware Road station a man helps an injured woman away from the scene.

9 of 12 Police across London are stretched as the underground network shuts down...

10 of 12 ..and people try to understand what is happening and make sure loved ones are safe.

11 of 12 London's Emergency Plan is put into action as medical staff rush to the scene and hospitals are on full alert.

12 of 12 UK Prime Minister Tony Blair said it was "reasonably clear" there had been a series of terrorist attacks. He said it was "particularly barbaric" that it was timed to coincide with the G8 summit, before flying back to London.