A Swedish woman has been arrested at Gatwick Airport on suspicion of committing a terror offence.
The 40-year-old was held just before 2.15pm on Thursday.
She had arrived at the UK's second busiest airport on a flight from Italy, a police spokesman said.
The South East Counter Terrorism unit said she was detained under Section 41 of the Terrorism Act 2000.
She was arrested on suspicion of commission, preparation or instigation of acts of terrorism.
She remains in police custody.
