An 18-year-old man from Grangetown in Cardiff has been arrested on suspicion of terrorism offences.
South Wales Police say he has been arrested under the Section 5, Terrorism Act 2006 for assisting in the preparation of an act of terrorism.
Police said that today's arrest was not linked to any immediate threat to public safety.
More top news
Runners looking to compete in the Newport half marathon have been disappointed again after it was cancelled due to weather warnings.
Very cold and windy. Some sunny breaks but plenty of snow showers feeding in the from the east.
A late goal from Andrew Hotham with 20 seconds remaining in the game sealed the win for the Cardiff Devils on Friday Night in Belfast.