Phil Beer was last seen trying to get free from the train wreckage

Phil Beer, 22, was on the underground with friend Patrick Barnes when the explosion struck between King's Cross and Russell Square on Thursday.

Although Mr Barnes could not see through the smoke he heard Mr Beer tell him: "I am OK".

His family are planning to visit London with poster-sized pictures of Mr Beer, from Borehamwood, Herts, in the hope of making contact with him.

He rang to say they had been on the train that the bomb had gone off on, but he couldn't find Phil Stacy Beer

Phil's mother Kim Beer, 47, said: "All we know is that they were standing in the middle of the carriage half way along when the bomb went off behind them. It went dark and smoke started coming in to the carriage.

"Patrick said: 'Phil where are you?' and Phil said 'I am ok, I am ok'.

"Phil then said 'I can't see you' and Patrick said 'We are going to die' and that's when Phil replied 'No we are not'."

Mr Barnes, 22, who suffered burns and a broken leg, managed to crawl from the wreckage and make his way to the platform at Russell Square where he used his mobile phone to contact Phil's sister, Stacy, 24.

Stacy said: "He rang to say they had been on the train that the bomb had gone off on, but he couldn't find Phil.

"He said he called out Phil's name and Phil answered but he hadn't seen him since."

Mrs Beer said: "The police have said just because they haven't found him doesn't mean he is dead. He could be in shock, traumatised and is wandering around London having lost his memory.

"He was not carrying any identification on him and he didn't have a mobile phone."

The family said Mr Beer, a hairdresser, would stand out in any crowd with his red and black hair and his lip stud and a tattoo of a Celtic dragon on his left arm.