Police arrested 12 men in early morning raids in three cities on Monday aimed at thwarting a major new terrorism plot against British targets.
Assistant Commissioner John Yates, Britain's senior counterterrorism police officer, said the suspects were detained in London, in the central English city of Stoke-on-Trent and in Cardiff, Wales.
"The operation is in its early stages so we are unable to go into detail at this time about the suspected offenses," Yates said in a statement. "However, I believe it was necessary at this time to take action in order to ensure public safety."
Police confirmed that the men were detained by unarmed officers - indicating that any attack was unlikely to have been imminent.
The arrests follow weeks of surveillance and are not believed to be linked to the suicide bombing in Sweden on Dec 11, or to recent concerns aired by European and US officials over purported plots to carry out Mumbai-style commando attacks on European cities.
Police said 11 of the suspects were arrested at or close to their homes at around 5 am, while the remaining man was detained at a property in the central English city of Birmingham.
Five of the arrested men are from Cardiff, four from Stoke-on-Trent and three from London, police said.
Officers said the suspects range in age from 17 to 28 and will be questioned on suspicion of commissioning, preparing or instigating acts of terrorism.
The arrests are the most high-profile antiterror raids in Britain since April 2009, when 12 men were detained in raids across northern England. All were released without charges, but authorities insisted they had thwarted a major al-Qaida bomb plot in the northern city of Manchester.
Yates said the latest arrests followed close coordination by officers from several different cities. "This is a large scale, pre-planned and intelligence-led operation involving several forces," he said.
A British security official, speaking on condition of anonymity because of the sensitive nature of his work, said the arrests did not relate to any planned holiday season attack. Iraqi officials had claimed last week that captured insurgents believed the Stockholm bombing was part of a series of planned al-Qaida attacks against the US and Europe during the Christmas season.
(中國日報網英語點津 Helen 編輯)
Todd Balazovic is a reporter for the Metro Section of China Daily. Born in Mineapolis Minnesota in the US, he graduated from Central Michigan University and has worked for the China Daily for one year.