A man has been arrested at Stansted Airport in Essex by counter-terror police who suspected he was planning to travel to Syria.
The 37-year-old was due to board a flight for Turkey on Tuesday evening when he was held on suspicion of preparing for acts of terrorism.
His arrest is not connected to Monday night’s suicide bomb attack at Manchester Arena, Scotland Yard said.
Two residential addresses in north London are being searched.
The UK’s terror threat level has been raised in the wake of the arena attack, which killed 22 people and injured 59.
It stands at its highest level of “critical”, indicating further attacks may be imminent.