A 49-year-old man has been arrested on suspicion of preparing acts of terrorism at Southend Airport.
The suspect was stopped by the Metropolitan Police, using powers under the Terrorism Act allowing them to stop anyone at Britain’s borders if they are believed to have committed or be planning a terror offence.
A spokesperson for Scotland Yard said he was taken to a police station in south London and remains in custody.
“Officers also carried out a search at an address in Essex, which is now complete,” he added. “Enquiries continue.”
Police gave no further details on Tuesday’s arrest, but the law has previously been used to stop people attempting to join Isis in its territories in Syria and Iraq.
Following a global crackdown on travel to Isis-controlled areas and the group's military losses, analysts have warned that it is urging supporters to instead launch terror attacks in their home countries.
Khuram Butt, the ringleader of the London Bridge terror attack, is among the terrorists who considered leaving for Syria before attempting atrocities at home.
A 17-year-old girl was charged with colluding with an Isis fighter she “married” online to launch a terror attack in the UK after her plan to reach Syria was thwarted last year.
According to Home Office figures, around 850 suspected jihadis have travelled to the so-called “caliphate”, with at least 15 per cent known to have been killed and just under half returning to the UK.
MI5 has over 500 investigations underway into 3,000 individuals across the UK who are assessed as posing the biggest threats, while there are another 20,000 other former subjects whose risk remains subject to review.
