Counter terrorism officers stopped a man at Stansted Airport on Sunday night.
He was arrested on Monday on suspicion of terrorism offences and has been taken to a London police station where he remains in custody.
The 21-year-old had returned to the UK from Istanbul, Turkey, via Stuttgart.
Detectives says the arrest was not in response to any immediate threat or risk. Detectives have carried out searches of three addresses in connection with this investigation.
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Lifeguards at Sea Palling where a swimmer died after getting caught in a rip-current, remind people to always swim at life-guarded beaches.
It will become cloudy this evening with a chance of showers arriving from the west. Lows of 15 deg C.
It's going to be another dry day with plenty of sunny spells and feeling humid. Highs of 27 deg C.