Officers from the Metropolitan Police Counter Terrorism Command stopped the man after he disembarked from a flight from Iraq on Thursday.

A statement from the Metropolitan Police said: "As a result of enquiries during the stop a decision was made to arrest the man under section five of the Terrorism Act - suspicion of preparation of terrorist acts.

"The man was arrested under PACE and taken to a central London policy station where he remains in custody."

It comes after a 31-year-old man arrested on Thursday in Norfolk on suspicion of fundraising for the purposes of terrorism and encouraging support for a banned terror group was bailed.

Scotland Yard said that arrest was related to suspected activities overseas. Two properties in east Norfolk and one in north London have also been searched.