Baku. 15 March. REPORT.AZ/ Two boys aged 17 from north-west London and a man aged 19 were returned to the UK on Saturday night, the Met said.
They have been arrested on suspicion of preparing terrorist acts and are being held at a police station in London.
They were reported missing on Friday and were detained after UK police alerted Turkish officials, it added.
Report informs referring to BBC, Scotland Yard said counter-terrorism officers had initially been made aware that the two 17-year-old boys had gone missing and were believed to be travelling to Syria.
Further enquiries revealed they had travelled with a third man, police added.
"Officers alerted the Turkish authorities who were able to intercept all three males, preventing travel to Syria," a police spokesman added.