LONDON Police in northern England arrested on Tuesday four men on suspicion of plotting terror attacks, according to a police spokesman.
The four suspects were detained by officers from the North East Counter Terrorism Unit at their homes in Sheffield, located in the county of South Yorkshire 255 kilometers (159 miles) to the north of London, and Chesterfield, Derbyshire some 20 minutes drive to the south , the source added.
The arrests were intelligence-led and pre-planned as part of an ongoing investigation by Counter Terrorism Policing North East, the police spokesperson said in a statement.
The four men aged 22, 31, 36 and 41 were being interrogated at a West Yorkshire police station while their homes were being searched.
We would ask people to remain alert, but not alarmed, and we are grateful for the assistance and understanding of people locally, the statement added, without providing further details on the operation.