Detectives are questioning four men as part of investigation
Counter-terrorism police and MI5 officers are still questioning the four men who were held yesterday as part of an operation to foil a suspected Christmas attack.
A security source told media that the group may have been planning to target a Christmas market in or around London.
Tuesday saw a series of raids in South Yorkshire and Derbyshire where armed police and an Army unit swooped on a flat above a fish and chip shop amid fears there may have been explosives at the property.
Three men, aged 22, 36 and 41, were detained at different addresses in Sheffield and a 31-year-old man was arrested in Chesterfield, police said.
The suspects are understood to have been under surveillance, but counter-terrorism officers decided to act amid concerns that they had moved beyond discussion and begun trying to source bomb parts or materials.
Counter-terrorism sources described the arrests as “significant”. They come at a time when police have stepped up security at possible seasonal targets including Christmas markets.