A 19-year old man has been arrested at Heathrow airport on suspicion of "preparing for acts of terrorism" in relation to Syria, police said.
The man is being held at a police station in London and an address in the north of the city is being searched, the Metropolitan police said in a statement.
More top news
An Irish nanny freed after baby murder charges in the US were dropped describes her 'nightmare' and branded the prosecution a 'scandal'.
A man became so frustrated with noise from a nearby building site that he shot a builder with an air rifle, police say.
A backbench revolt over proposals to ease purdah restrictions on the EU referendum has led to a government climb down.