A mobile phone belonging to a missing man has been found among the debris of Thursday's bus explosion, his colleagues said Friday.

Friends of Jamie Gordon have launched a desperate campaign for news of his whereabouts.

Colleagues at City Asset Management (search), based in Old Street, said the administration assistant had called his office to let them know he was traveling to work on board the bus, but he has not been heard from since.

Friend Sandy Reeve, a colleague at the firm, said Mr. Gordon's mobile was recovered Friday morning among the debris found close to the site of the bus explosion.

She said: "There are teams of people from the office out all over London this morning putting up posters and trying to find out any information that they can.

"His girlfriend, Yvonne Nash, is frantic with worry. She's been trying to find out whatever she can and is desperate for some information.

"She works for Orange, the mobile phone company, and was able to get a trace done on his last call from his mobile, which turned out to be right at the scene of the explosion."

Colleagues stuck up makeshift missing posters this morning across the Tavistock Place (search) area and at scenes of the other explosions.

The notes featured a photograph taken on Wednesday night, hours before the terrorist attack, and conjured up echoes of New York in the aftermath of Sept. 11, when similar appeals were plastered across the city.

"We just hope to find out what has happened to him,"said Ms. Reeve.

"We think he was on the bus, we had a call from him at about 9:40 a.m. or 9:42 a.m. He said he was on a bus from Euston. It's absolutely terrible, we still can't believe it, it still hasn't sunk in."

She said Mr. Gordon had worked for the company for around eight or nine years and had spent part of his early life in Zimbabwe (search).

It is believed that his father lives in Scotland.

"We haven't been able to get hold of his family as yet, but that's what we are trying to do. We want to tell them that we are doing everything we can and that we're just trying to find out what has happened."

A helpline has been set up for anyone with information about Mr. Gordon.

Miss Nash asked anyone who knew anything about his whereabouts to call (011 44) 0207 984 2000.

The posters, attached to walls and trees on every street surrounding the blast site, show Mr. Gordon smiling and dressed in a pink shirt and pink tie.

The appeal reads: "Have you seen this man?

"Please help us find our friend who is missing following yesterday's bombings.

"These pictures were taken Wednesday night and he will have been wearing the same clothes.

"He is 30 years old and has medium-length brown hair and is 5-foot-11. He has a red tattoo on his left shoulder."

Miss Nash, 30, an events marketing manager for the mobile phone company Orange, said earlier that she had logged his details with the police casualty bureau and had been frantically telephoning hospitals all night.

She said Mr. Gordon would not normally have taken that route to work, but had stayed at a friend's house the previous evening following a night out.

She said there appeared to be "no other explanation" but that he had been on the No. 30 bus devastated by the blast.

"The worst-case scenario is that he is dead," she said.

"We just have to find him. If he is hurt and on his own in hospital, we need to be with him. It is shocking to think he has been through something that traumatic and we cannot be with him."

Miss Nash, who has lived with Mr. Gordon in Enfield, north London, for seven years, said she was desperate for news.

"I just have to find him," she said. "I have to know what happened. You cannot sleep, cannot eat when you are that worried about somebody.

We don't know where he is and we are just desperate to find out. We are just trying to keep going. Is he dead? Is he alive? Not knowing is dreadful."

Home Secretary Charles Clarke said Friday: "People are trying to help desperately and I am very sorry indeed for the situation Yvonne Nash is experiencing."

Meanwhile the brother of a woman missing since yesterday morning arrived at London's University College Hospital (search) seeking information about her.

David Webb, 38, said other family and friends were visiting various hospitals in the search for Laura Webb, 29.

He said she was last seen by her boyfriend at 9 a.m. Thursday at her home in Islington, north London, as she was setting off to her place of work. She works as a personal assistant.

Mr. Webb, a teacher, from Kingston-upon-Thames, southwest London, said: "We are very upset about her disappearance, and all the options go through your mind. They include that she may be being cared for somewhere, or maybe she is still underground."