Three men and a woman were arrested Thursday night in Birmingham, England, and one man was arrested at London's Gatwick Airport early Friday in an operation involving British, French and Belgian authorities, NBC News reported.
A spokeswoman for West Midlands Police would not say specifically whether the detentions were linked to arrests in France and Belgium relating to terror attacks in both countries. A British security source, however, told NBC News the arrests were "Paris- and Brussels-related."
The source, speaking on condition of anonymity, said the British investigation focused mainly on Mohamed Abrini, who allegedly confessed to being the so-called "Main in White" who was among the Brussels airport bombers.
The five suspects were being questioned by counter-terror officials Friday.