Armed officers from the Civil Nuclear Constabulary have been called out to a Sheffield street, after police received reports of man acting suspiciously from a concerned member of the public.
South Yorkshire Police confirmed they, along with officers from the CNC, successfully located and detained a man on Surrey Street in the city centre yesterday afternoon.
A South Yorkshire Police spokesman said of the incident: "The man was questioned by officers and assessed by a specialist mental health team who determined that he was no risk to the public and safe to leave.
"All resources on scene very quickly - effective teamwork."
The specialist officers in the city to provide support throughout the next seven days but Operation Temperer will provide military support across the UK for as long as it is needed.
The CNC officers are under the command and control of South Yorkshire Police.