Counter terrorism police searched a house in Walsall and a number of other properties
Two men aged 21 and 27, and one woman aged 21 have been arrested in Walsall, West Midlands, on suspicion of Syria-related terrorism offences.
The trio were detained at their home addresses at 06:00 BST on Tuesday.
They are being held at a station in the West Midlands Police area.
Searches are now being carried out at eight associated addresses in the Walsall area and one in Moseley, Birmingham.
Police said the operation, undertaken by officers from the West Midlands Counter Terrorism Unit, was "pre-planned and intelligence-led".
There was no immediate threat to public safety, they said.
The arrests were made under terrorism legislation, meaning officers have an initial 48 hours to question the suspects before charging or releasing them, or applying for a warrant of further detention.
