Eyewitness stories from FoxNews.com:
The head of Scotland Yard said in a brief press conference Thursday that commuters and other Londoners should stay exactly where they are; he said it's possible more portions of the transit system will be shut down.
Some witnesses said they heard gunshots at the Warren Street stop but according to Sky News, police believe those noises were actually detonators going off for bombs that didn't explode.
"People were panicking. But very fortunately the train was only 15 seconds from the station," witness Ivan McCracken told Sky News.
McCracken said he smelled smoke, and people were panicking and coming into his carriage. He said he spoke to an Italian man who was comforting a woman after the evacuation.
"He said that a man was carrying a rucksack and the rucksack suddenly exploded. It was a minor explosion but enough to blow open the rucksack," McCracken said. "The man then made an exclamation as if something had gone wrong. At that point everyone rushed from the carriage."