The terror-related arrest of a teenager at Heathrow airport was not made in response to any immediate risk or threat, police said.
A 19-year old man has been arrested on suspicion of "preparing for acts of terrorism" in relation to Syria.
The man is currently held at a police station in London.
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Accused Darren Osborne was a "ticking time-bomb" who had become "obsessed" with Muslims in the weeks before the incident, a court has heard.
Ukip's ruling committee unanimously backed a vote of no confidence in Mr Bolton on Sunday and six key party figures have also resigned.
A much improved day across the UK. Rain spreads in through this evening and overnight with the heaviest bursts across western Scotland.