'We thought we were going to die'

A general view of the scene following an explosion at Aldgate underground station in London. Picture / Reuters

LONDON - A London commuter has talked of the moments her fellow travellers thought they were going to die after an explosion rocked their underground train today.

The blast on the train between King's Cross and Russell Square tube stations in central London is believed to have killed at least 23 passengers.

Three further blasts on London's transport system also claimed up to 18 lives, while it is believed more than 1,000 people have been injured.

Zeynep Basci, 21, boarded the front carriage of a packed train at King's Cross station at around 9.40am and felt an explosion shortly after the train pulled out.

"We all thought we were going to die," Basci said as she sat in shock on the steps outside an office in Russell Square.

"Ten seconds after we left the station there was an explosion and everything went pitch black and all the windows were smashed up and there was glass everywhere and the carriage was full of smoke, everybody was choking.

"People were screaming, some were unconscious on the floor. We were just yelling trying to tell people to stay calm but there was so much screaming.

"We forced open a door to let some air in.

"We thought we'd hit something, we didn't think it was a bomb.

"We got a message from the driver who said everything was OK. After about 10 minutes, because we were in the front carriage, we got through the driver's door and walked through the tunnel to Russell Square.

"When we got out of Russell Square station, the police were shouting at us to run.

"I don't know about the others on the train."

Blasts also hit trains at Aldgate East, Edgware Road and on a double decker bus at Tavistock Square, next to Russell Square.

- AAP