LONDON // Police believe they have thwarted a major al Qa'eda plan to bomb British cities following the arrest yesterday of 12 men.
The suspects, aged between 17 and 28, were arrested in pre-dawn swoops on homes in London, Cardiff and Stoke-on-Trent in central England.
Intelligence sources said yesterday that the men had been under surveillance by MI5 and counter-terrorism police for some weeks and were still at the planning stage of the attacks, which were not imminent.
All remained in custody last night after being arrested on suspicion of the commission, preparation or instigation of an act of terrorism in the UK.
"This is a large-scale, pre-planned and intelligence-led operation involving several forces, said John Yates, an assistant commissioner at Scotland Yard and the head of counter-terrorism policing. "The operation is in its early stages so we are unable to go into detail at this time about the suspected offences.
"However, I believe it was necessary at this time to take action in order to ensure public safety."
A police spokesman added that 11 of the suspects, several of whom are understood to be United Kingdom citizens of Bangladeshi origin, were arrested at or near their homes while the 12th was detained at a property in Birmingham.
"Searches are now being conducted at the home addresses, plus the address in Birmingham and another residence in London," the spokesman added.
The arrests followed the disclosure last week that Iraq-born Taimour Abdulwahab al Abdaly, who blew himself up in an unsuccessful suicide bombing in a shopping district of Stockholm, had been living in the English town of Luton for the past nine years.
Abdaly, however, is not believed to have been connected to the dozen arrested yesterday. In September, US intelligence sources indicated that they had uncovered information suggesting that al Qa'eda was planning a series of coordinated attacks in Britain, France and Germany.
The suggestion at the time was that Islamic extremists were planning copycat attacks of the 2008 raid in Mumbai, when 10 gunmen went on a rampage and killed more than 160 people.
Last week, Iraqi officials claimed that captured insurgents had indicated the Stockholm bombing was part of a series of attacks planned over the Christmas period, but this idea was rejected by both British and German government sources.
Police pointed out yesterday that the plans associated with the dozen arrested men were not nearly far enough advanced to mount attacks over Christmas.
Five of those arrested were from Cardiff where Ramesh Patel, a local councillor and community leader, was alerted by police after the men were taken into custody.
"It is a shock for me. Cardiff is not one of those places where you would expect this, although I realise it can happen anywhere," he said.
"I have to praise police for acting on the information they had very quickly and hopefully these are the right people they have arrested and the problem will be dealt with."