Counter-terrorism officials are investigating whether two men arrested by armed police were involved in a potential plot to attack the UK.
The arrests were described as “significant” and took place on Tuesday afternoon, first in north London and then Birmingham. Police chiefs assessed that armed officers were needed to make the arrests, which come as security officials fear fresh terrorist attacks are being planned.
The arrests followed a decision by counter-terrorism police and MI5, the domestic security agency, after a joint operation.
The men, who were arrested within 100 minutes of each other, are aged 21 and 20. They were in custody and being questioned and searches were under way in London and Birmingham.
The two men were arrested on suspicion of being involved in the commission, preparation and instigation of terrorism, contrary to section 40 of the Terrorism Act 2000.
Police gave few details about the arrests, which were made by officers from the Metropolitan police’s counter-terrorism command, firearms officers and the counter-terrorism unit covering the West Midlands
In a statement, the Met said: “The officers arrested a 20-year-old man in north London and a 21-year-old man in south-east Birmingham at approximately 14.50hrs and 16.30hrs respectively on Tuesday 28 November.
“Both are being detained in custody under the Terrorism Act at a south-east London police station. Searches at addresses in south-east Birmingham and north London are ongoing. “
Police and MI5 say they have disrupted a series of attack plots this year on top of five attacks that got through undetected. Four were linked to violent Islamism and one to an extreme rightwing ideology.