THERE are growing fears that three of the July 21 bombing suspects returned to their bomb factory flat to retrieve explosives in order to launch more attacks in London.

A witness claimed that, after the failed terrorist attacks last Thursday, she saw three men visit the one-bedroom council flat on the ninth floor of a 12storey block in New Southgate, north London, where two of the suspects lived.

NeighbourTanya Wright said she was coming out of the lift when she noticed three men standing outside the flat. "They looked at me and looked very suspicious and jumped back into the flat . . . I made nothing of it until the police woke us at 1am, " she said.

The revelation came as explosives experts examined a "large amount" of bomb-making material found at the flat and other material, possibly linked to the July 21 terror attempts, at a nearby underground garage.

Yesterday evening, a cordon erected around a white VW Golf on London's north circular road near Finchley, a few miles from New Southgate, was lifted after the carwas checked for explosives.

The vehicle had been under surveillance and was seized on suspicion it was linked to one of the men. People living nearby were evacuated as police checked it for evidence.

Earlier, the Home Office revealed the immigration status of the two named suspects, saying they had been legal residents in the UK for more than 10 years.

Yasin Hussan Omar, 24, the suspected failed Warren Street bomber, is a Somali who arrived in Britain aged 11 in 1992 as a dependant of an asylum-seeker.

He was granted exceptional leave to remain in Britain and, in May 2000, was granted indefinite leave to remain.

Muktar Said Ibrahim, 27, the suspected failed Hackney bus bomber, arrived in Britain from Eritrea also as a dependant of an asylum-seeker in 1992, aged 14.

In November 2003, he applied for naturalisation as a British citizen and was issued with his passport last September.

It was also claimed Omar had received thousands of pounds in benefits in recent years. He was given pounds -75 a week to pay for the New Southgate flat, where he has been the registered tenant since February 1999. His housing benefit stopped in May this year.

Neighbours insisted Ibrahim had also been staying at the flat. Witnesses have described seeing men lugging boxes into the flat only a fewweeks ago;

the men said they contained wallpaper stripper.

Last night, Ibrahim's family issued a statement. It read: "We are a peaceful family . . . We were shocked when we saw Muktar's picture in the national news. We immediately attended the police station and made statements to the police.

We would suggest that anyone with information contacts the police."

The family explained how Ibrahim left the family home in 1994 and had not visited them formonths.

"The family wish to express their shock regarding recent events and in no way condone any acts of terrorism, " the statement added.

The level of police frustration in the huge manhunt is thought to be mounting as, six days on from the attempted bombings, none of the four or possibly five would-be bombers has been tracked down.

Detectives have no evidence they have left the country and believe they may all be hiding in a safe house in the capital.

They believe the London terrorists could have links with the Yorkshire suicide cell which carried out the four bombings on the London transport network on July 7, killing 56 people, including themselves.

Detectives are investigating whether some of the July 21 suspects might have visited the same Welsh whitewater rafting centre as two of the July 7 suicide bombers.

Five people have so far been arrested in connection with the failed bombings and held under anti-terror laws.