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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Jeremy Corbyn has denied allegations of bullying saying "intimidation is not allowed" in the Labour party.
A gunman who killed nine people and at a Munich shopping centre was German-born and had no links with Islamic State, authorities say.
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