British police say a seventh man has been arrested in a counterterrorism operation that began earlier this week.
West Midlands Police said Thursday the 20-year-old was detained in the central England city of Birmingham, on suspicion of "the commission, preparation or instigation" of a terrorism act.
Six other men, aged 25 to 32, were arrested Monday in the same city. Officials said the arrests related to Islamic extremism and were one of the year's most significant anti-terror operations.
Police said they had been given until midnight Sunday to charge the men, release them or apply for a further extension.
Terrorist suspects can be held for up to 14 days before they must be charged or released.