Five people from Birmingham have been arrested after an anti-terror inquiry involving MI5 and authorities in Belgium and France.
West Midlands Police said the arrests of five suspects in the UK formed part of an extensive investigation into "any associated threat" to Britain following terrorist attacks in Paris and Brussels.
Detectives detained three men, aged 26, 40 and 59, and a 29-year-old woman in Birmingham on Thursday night, while a 26-year-old man was arrested at Gatwick Airport in the early hours of Friday.
Assistant Chief Constable Marcus Beale, of West Midlands Police, said a number of properties in Birmingham were being searched after the pre-planned and "intelligence-led" arrests.
Mr Beale said in a statement: "This action forms part of an extensive investigation by West Midlands Counter Terrorism Unit, together with the wider counter terrorism network, MI5 and international partners including Belgian and French authorities to address any associated threat to the UK following the attacks in Europe.
"There was no risk to the public at any time and there is no information to suggest an attack in the UK was being planned."
All five people arrested were held on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
The arrests were made five months after the November 13 attacks in Paris, which left 130 people dead.
West Midlands Police has previously refused to confirm reports that images of landmarks in Birmingham, including a shopping mall, were found on a mobile phone belonging to a ring-leader involved in the Paris atrocities.