A man and a woman from Birmingham have been arrested on suspicion of possessing documents likely to be of use to someone committing or preparing an act of terrorism.
The two, a brother and sister aged 23 and 18, were arrested this morning in the Small Heath area of the city.
The arrests are said to have been pre-planned and police say they were not made in response to any threat to public safety.
Computers and other electronic devices which will undergo forensic examination.
Officers say a number of files need to be investigated, which is likely to take some time.