Three teenagers have been arrested on suspicion of preparation of terrorist acts.
Two 17-year-old boys from north-west London and a 19-year-old male returned to the UK at about 11.10am on Saturday (March 14), after Turkish authorities were alerted to intercept their plans to travel to Syria.
All three were arrested on suspicion of preparation of terrorist acts contrary to Section 5 of the Terrorism Act 2006.
They were taken to a central London police station and were later bailed until a date in early May, pending further enquiries.
Officers from the Metropolitan Police's counter terrorism command (CTC) were first made aware the two boys aged had gone missing and were believed to be travelling to Syria on Friday March 13.
Further enquiries revealed they had travelled with a third male aged 19.
Officers alerted Turkish authorities who intercepted all three males, preventing them from travelling to Syria.
Police enquiries continue.