The four men are being held on suspicion of fundraising in Britain for terrorist purposes and of traveling to Pakistan for terrorist training.

Three men aged 19 and one aged 24 were detained by officers from the West Midlands Counter Terrorism Unit at their home addresses in the Sparkhill area of England’s second city.

Eight people arrested in September have already been charged in connection with an ongoing investigation, known as Operation Pitsford. Seven are currently on remand after appearing in court.