Cars and mobile phones led to rapid arrests

Presented with two intact cars in London containing a wealth of clues and evidence, and two suspects caught while mounting an attack in Glasgow, Britain's security services have moved at lightening speed to apprehend eight suspects over the past 72 hours.

The saloons parked outside the Tiger Tiger nightclub and in nearby Cockspur Street in central London had both been taxed, both had histories which could be traced, and contained mobile phones, fingerprints, DNA evidence and bomb equipment which yielded further information.

They have become the source of the most vital leads, providing alleged links to addresses in Newcastle-Under-Lyme with the Saudi-born Jordanian Mohammed Jamil Abdelqader Asha, a neurosurgeon, the Renfrewshire home of the Iraqi doctor Bilal Abdulla, and other addresses in Liverpool including the home of a 30-year-old man who was disabled with a taser gun by police after they stopped his car.

In the immediate aftermath of the attempted bombings, both cars were swabbed for traces of DNA to build genetic profiles of the attempted bombers. The movements of the mobile phones left in the cars were tracked through their signals and their call records were examined. It was that examination that is believed to have led the police to apprehend Mohammed Asha and his wife on the M6 on Saturday.

The letting agent for Mr Asha's house in Newcastle-under-Lyne, Daniel Gardiner, said officers traced his company after tracking phone records linked to the foiled London car-bomb attacks. He said: "The police wanted to know why we had dialled a certain phone number. They had the phone records from the situation down in London. We had made a phone call in regard to the tenant at that house. We could find no record of contacting that number, but the police had got detailed phone analysis."

The police are also seeking any garages that may have had requests for unusually large sales, and are tracking the gas cylinders by their identifying marks.

The bombers had, according to a security source, tried to detonate the car outside Tiger Tiger with four telephone calls, and the one at Cockspur Street twice. But the bombs failed to explode due to a technical mistake made by the makers.

The two Mercedes had also been parked in an area with one of the highest concentrations of CCTV cameras in the country. The police are said to have found images of suspects who may have driven the cars to central London. Teams of officers have spent the past 72 hours sifting through all available CCTV footage.

The wreckage left by the Glasgow airport attack has also provided potentially valuable evidence. The Jeep was badly damaged, but even with that vehicle the police say they were able to find worthwhile information, especially from the propane gas cylinders which had not exploded and carried identification marks.

According to security sources, members of the group had moved to Britain between 15 months and two years ago. They had avoided mixing with known Muslim extremists in the country, or frequenting places such as mosques with fundamentalist preachers or Islamist bookshops. "They have given the appearance of being professional people, religious, but not overtly political", said one police source yesterday.

A flurry of communication between MI6 and MI5 to intelligence services in the Middle East is also said to have assisted in the identification of the suspects and their associates.

Although the most high- profile Muslim terrorist cases in this country had involved "home-grown" radicals, both MI5 and Scotland Yard's Special Branch had been aware of activities by foreign groups. Questions will invariably be asked as to how a sleeper cell managed to remain undetected and almost succeeded in carrying out the "spectacular" attack the al-Qa'ida leadership had promised.

The extent of the carnage that could have been caused had the devices successfully exploded was revealed yesterday by a military forensic laboratory in Kent.

Experts said the London bombs could have generated a massive fireball spraying a wave of 200 litres of petrol and nails a hundred feet wide. The third bomb, in the jeep that rammed into Glasgow airport, was smaller in size, but still possessed the capacity to inflict enormous damage.