Detectives are continuing to question five people detained in the UK after an inquiry into a suspected terror cell reportedly linked to the Paris and Brussels attacks.
Four men and a woman from Birmingham were arrested on Thursday and Friday after an investigation involving MI5 and authorities in France and Belgium.
West Midlands Police said the arrests formed part of an extensive inquiry into "any associated threat" to Britain following terrorist atrocities in the French and Belgian capitals.
Detectives detained three men, aged 26, 40 and 59, and a 29-year-old woman in Birmingham on Thursday night.
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: "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.
It comes just a week after the arrest of Mohamed Abrini, who admitted being the "man in the hat" pictured alongside two suicide bombers who blew themselves up at Brussels Airport last month.
Some 32 people were killed and nearly 300 were injured in suicide blasts at the airport and the city's Maelbeek subway station.
Abrini was the last identified suspect still at large following 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 ringleader involved in the Paris atrocities.