In the biggest anti-terrorist sweep in Britain in nearly two years, police have arrested a dozen men accused of plotting a large-scale terror attack on targets inside the UK.
The suspects, who ranged in age from 17 to 28, had been under surveillance for weeks and were believed to have links to Pakistan and Bangladesh, officials said.
The arrests come amid growing concerns in Europe over terrorism following a suicide bombing in Sweden and reported threats of a terror attack on a European city modeled on the deadly shooting spree in Mumbai, India.
Police swooped in before dawn on Monday in coordinated raids on houses in four cities — London, Cardiff, Birmingham and Stoke-on-Trent. The officers were unarmed, suggesting any planned attack was not imminent.
The joint operation by domestic spy agency MI5 and police was the largest since April last year, when 12 men were detained over an alleged al-Qaeda bomb plot in Manchester.
Counterterrorism officials declined to give more details of the latest alleged plot, saying only that the men had been under surveillance for several weeks. No details were given as to whether explosives or arms were found, and searches were under way in the homes where the arrests took place.
“The operation is in its early stages so we are unable to go into detail at this time,” said John Yates, Britain’s senior counterterrorism police officer.
Still, he said Monday’s raids, involving a dozen suspects across the UK, indicated they were planning something big.
“This is a large scale, pre-planned and intelligence-led operation involving several forces,” Yates said.
Police have up to 28 days to question the suspects before they must be charged or released.
The men are thought to be British nationals with links to Bangladesh and Pakistan, according to a counterterrorism official who spoke on condition of anonymity.
The arrests were not believed to be part of any planned holiday season attack, said a British security official who also spoke on condition of anonymity.