According to BBC News, at least two persons were killed and dozens were injured in the blasts.

Those who survived the terrorist attack, describe scenes of horror.

Simon Corvett, 26, from Oxford, was on the eastbound train leaving Edgware Road Tube station when the explosion happened.

He said: "All of sudden there was this massive huge bang. It was absolutely deafening and all the windows shattered.

"The glass did not actually fall out of the windows, it just cracked.

"The train came to a grinding halt, everyone fell off their seats."

Mr Corvett, who works in public relations, said the commuter train was absolutely packed.

"There were just loads of people screaming and the carriages filled with smoke," he said.

"You couldn't really breathe and you couldn't see what was happening. The driver came on the Tannoy and said `We have got a problem, don't panic'."

Mr Corvett, whose face was covered in soot, joined other passengers to force open the train doors with a fire extinguisher.

He said the carriage on the other track was destroyed.

"You could see the carriage opposite was completely gutted," he added.

"There were some people in real trouble."

Sarah Reid, 23, a student doing work experience, was on the carriage next door to the one which was struck by the explosion.

Speaking after the ordeal, having been led out down the track, near Liverpool Street station, she told how she saw a carriage ripped apart with the roof blown off.

"I think some people may have died," she said.

The blast had pulled some people's clothes off.

She added: "I was on the train and there was a fire outside the carriage window and then there was a sudden jolt which shook us forward.

"The explosion was behind me.

"Some people took charge. We went out of the back of the carriage."

She said the explosion happened at 8.50am but she was not able to get off the carriage until 9.30am.

Miss Reid said an announcement came on but cut off after saying: "Hello".

"There was really hard banging from the carriage next door to us," she said, describing events immediately after the blast.

"That was where it happened," she added.

She said there was a fire which she had seen initially outside the window of her carriage.

Describing being led away from the scene, she said: "A carriage was split in two, all jagged, and without a roof, just open.

"I saw bodies, I think."

A British Transport Police (BTP) spokesman said that two trains remained stuck in tunnels at Edgware Road, but it is not known if they have collided or if passengers remain onboard.

"It's difficult to know exactly what is going on at the moment," he said.

"The initial report came from Liverpool Street, but there are incidents occurring across the network."

A man who survived the Aldgate blast told of passengers' terror when their train ground to a halt.

Arash Kazerouni, 22, said: "There was a loud bang and the train ground to a halt. People started panicking, screaming and crying as smoke came into the carriage.

"A man told everyone to be calm and we were led to safety along the track."

Mr Kazerouni, from Edmonton, North London, said: "Everyone was terrified when it happened.

"When they led us to safety, I went past the carriage where I think the explosion was. It was the second one from the front.

"The metal was all blown outwards and there were people inside being helped by paramedics.