THE scale of the terrorist threat facing Britain was revealed last night as police questioned a suspected would-be suicide bomber captured in a dramatic armed raid by police and MI5.

Yasin Hassan Omar, a 24-year-old Somalian, was felled with a Taser stun gun when officers stormed the safehouse where he was hiding in Birmingham early yesterday.

About 100 homes were then evacuated as the bomb squad moved in, sparking fears that the man had been on the verge of blowing himself up.

One report suggested he had a rucksack with him, which was thrown clear through a window by a police officer.

Police confirmed last night that the man was Omar, who tried but failed to blow up a Tube train near Warren Street last Thursday. He is the first of the July 21 suicide squad suspects to be caught.

Police are still hunting three other suspects over the attempted bombings.

As Omar was taken to Paddington Green high security police station, in London, by the Anti-Terrorist Branch, it emerged that the cell responsible for the July 7 attacks that killed 52 commuters had access to more bombs.

This sparked fears that more suicide attacks were planned.

Unnamed sources told the US network ABC News that 16 bombs were found in a car believed to have been rented by suicide bomber Shehzad Tanweer, who blew himself up on a train at Aldgate on July 7.

The car was discovered five days later at Luton railway station where Tanweer and his fellow bombers had boarded a train to London.

Inside were homemade high explosives, flat-packed like pancakes. And one image showed large nails bulging out of the side of a bottle-shaped bomb.

Previously unseen pictures of the bloody aftermath of the July 7 bombings were also broadcast by ABC News.

They showed the carnage inside the train near King's Cross on which bomber Germaine Lindsay killed himself and 26 others.

The sides, roof and floor of the train had been blown apart and wires dangled down across what remained of the mangled, twisted carriage.

In Birmingham, the man believed to be Omar was found at a maisonette, in Heybarnes Road, which had been under surveillance.

Neighbour Andy Wilkinson, an electrician, said he saw him being led out in a white forensic suit with his hands bound by plastic ties.

Shortly after the man was arrested, three other men were held in a raid two miles away in Bankdale Road, Washwood Heath, Birmingham. Those three men are being held in Birmingham.

Neighbours said three Somalian men had been staying in the semi-detached property.

Anti-terrorist police also raided two houses in Finchley and Enfield, both north London, at 6am but there were no arrests.

At least three would-be suicide bombers from the failed July 21 attacks are still on the run. They include Muktar Said-Ibrahim, 27, whose picture has been released by police.

Detectives fear the suspects may be in possession of explosives. They are investigating reports from neighbours that, the day after the failed attacks, some of them returned to a tower block flat they had used as a bomb factory in New Southgate, north London.

Officers believe that if the July 21 bombers had been successful, the loss of life could have been worse than the attacks on July 7.

* Tony Blair insisted yesterday that it was "sensible" for politicians to take holidays despite the London bombings and said he will jet off next week.

Home Secretary Charles Clarke has been widely criticised for flying out on a summer break yesterday as the manhunt continued.

But the Prime Minister said no one was ever more than a few hours away