A 17-year-old boy is among five people arrested on suspicion of being members of a banned far-right terrorist group.
The youth, from Nottingham, was arrested by counter-terrorism officers after a series of raids across the country, West Midlands Police said.
Two men, aged 22 and 28, both from Birmingham, a 23-year-old man and a woman, 22, both from Halifax, West Yorkshire, were all arrested on Wednesday.
The five have been detained on suspicion of being members of a proscribed organisation, National Action, which was banned in December 2016.
They are all being held at a police station in the West Midlands, after an operation carried out by West Midlands Counter Terrorism Unit in conjunction with CTP North East and East Midlands CTIU.
A number of addresses are also being searched in connection with the arrests.
A police spokesman said: “The arrests were pre-planned and intelligence-led.”