Twelve men have been arrested during a major anti-terrorist operation, West Midlands Police said.
The men – five from Cardiff, four from Stoke-on-Trent and three from London – were detained on suspicion of the commission, preparation or instigation of an act of terrorism in the UK.
The suspects, aged between 17 and 28, were detained by unarmed officers about 0500 GMT.
Officers are now conducting searches at the men’s homes and other addresses.
West Midlands Police said in a statement: “All were arrested at or near their home addresses, with the exception of one suspect from Stoke who was at a domestic property in Birmingham.
“Searches are now being conducted at the home addresses, plus the address in Birmingham and another residence in London.
“The suspects will be held at police stations in central London, the North West and the West Midlands.”
Metropolitan Police Assistant Commissioner John Yates, national lead for counter-terrorism policing, said it was a “large-scale, pre-planned, intelligence-led” operation involving several forces.
“The operation is in its early stages so we are unable to go into detail at this time about the suspected offences,” he said.
“However, I believe it was necessary at this time to take action in order to ensure public safety.”
The BBC’s Danny Shaw said counter-terrorism sources had described the operation as significant and it was related to an investigation into al-Qaeda-inspired terrorism.
“The suspects are believed to have been involved in a plot against targets in the UK,” he said. “This is not believed to have been a potential plot of a Mumbai-style attack, but a plot involving explosives or bombs.”
‘Not imminent plot’
Our home affairs correspondent said the officers who arrested the men were unarmed, suggesting the police felt there was no serious threat against them.
He added that some of the suspects were from Bangladesh, it was probably not an imminent plot and was not linked to the recent suicide bombing in Sweden.
Earlier this month, Iraq-born Taimour Abdulwahab al-Abdaly blew himself up in the Swedish capital Stockholm. He had been living in Luton and had been thrown out of one of the town’s mosque in 2007 for advocating violence, but he had not been reported to the authorities.
In September, intelligence sources said they had uncovered the early stages of an al-Qaeda plot to carry out co-ordinated attacks in the UK, France and Germany.
It was thought militants were planning to copy the 2008 attacks in the Indian city of Mumbai, where 10 gunmen went on a three-day rampage, killing 166 people.
The UK’s terror threat level is “severe”, the second-highest rating, meaning a terrorist attack is highly likely.
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