SIX men and one woman were arrested overnight in Birmingham as part of a "large pre-planned" counter-terrorism operation, West Midlands Police said. The men, aged 25 to 32, were taken into custody by unarmed officers in the Moseley, Sparkbrook, Sparkhill, Ward End and Balsall Heath areas of Birmingham between 11.30pm last night and 1am today. A 22-year-old woman, from Saltley, Birmingham, was nicked at 6.30am on suspicion of failing to disclose information contrary to the Terrorism Act 2000. The suspects are being held for questioning at an unnamed police station. Specialists are searching their homes and seven other properties around Birmingham. In a brief statement, West Midlands Police's Assistant Chief Constable for Security Marcus Beale said: "The operation is in its early stages so we are unable to go into detail at this time about the nature of the suspected offences."However, I believe it was necessary to take action at this time in order to ensure public safety." The arrests are not thought to be connected to the Lib Dems' autumn conference at the city's International Convention Centre. Anyone with information to assist the inquiry, which is being led by the West Midlands Counter Terrorism Unit, is asked to call the confidential Anti-Terrorist Hotline on 0800 789 321.