Some eyewitness reports:
UNNAMED AMERICAN TOURIST, RUSSELL SQUARE
We saw the bus go past us - the one that was blown up. We heard the explosion, turned around immediately, and saw the bus go straight up, the whole top of the bus, everything.
There was metal, there was wood, everything just straight up in the air.
We did not see any bodies. They got us off the street so fast, and around the corner because they said there could be a second blast.
It was horrible to think that I just saw those people alive and now they could be dead.
LOYITA WORLEY, LIVERPOOL STREET
"All the lights went out and the train came to an immediate halt.
There was smoke everywhere and everyone was coughing and choking, but remained calm. We couldn't open the doors."
She was in a carriage next to one where an explosion happened.
She said the adjacent carriage was "black on the inside". She saw people who appeared to have their clothes blown off, and bodies lying inside the carriage.
SCOTT WENBOURNE, ALDGATE
I saw three bodies on the track. I couldn't look, it was so horrific. I think one was moving but I'm not too sure.
There were also, I think, some bodies in the carriage, some were moving but I couldn't really look. No-one was attending to them.
We walked to the platform, which took about half an hour as there were so many of us, after all it was rush hour.
There were police at the platform and some of the injured were tended to.
TERRY O'SHEA, ALDGATE
I was in the third carriage, the one behind the one where the explosion was.
There was a loud bang and we felt the train shudder. Then smoke started coming in to the compartment. It was terrible.
People were panicking, but they calmed down after one or two minutes.
As they led us down the track past the carriage where the explosion was, we could see the roof was torn off it, and there were bodies on the track