A man has been arrested on suspicion of Islamist-related terrorism offences.
Detectives searched an address at 05:00 GMT in Worthing, West Sussex, and arrested the 20-year-old on suspicion of being involved in the commission, preparation, or instigation of an act of terrorism.
Counter Terrorism Policing South East say the arrest was intelligence-led and part of a pre-planned operation.
The man arrested remains in police custody.