Four men have been arrested under the Terrorism Act as part of a major ongoing investigation, police said.
Officers from the West Midlands Counter Terrorism Unit detained the men at their homes in the Sparkhill area of Birmingham on suspicion of travelling to Pakistan to undertake terrorist training and of raising funds for terrorist purposes.
A police spokesman said the suspects, aged between 19 and 24, had been arrested as part of Operation Pitsford, a large-scale inquiry which has already seen eight other people charged with a variety of offences.
A police spokesman said: “Today’s arrests were pre-planned and not made in response to any immediate threat to public safety.”
Eight people arrested in September have already been charged in connection with the investigation and seven of them are currently on remand after appearing in court.