A female member of staff sustained a serious head injury on Wednesday afternoon following an alleged assault at Kirkcaldy Job Centre.
Police attended the building following reports a woman had been attacked with a weapon.
The alleged incident happened in full view of other staff members and member of the public.
The woman was taken to the Victoria Hospital in Kirkcaldy by ambulance.
Police were quickly on the scene and a man was detained.
There was intense police activity in the area of Hunter Street with uniformed and CID officers present.
Officers were seen carrying evidence bags from the premises.
An Ambulance Service spokesman said: “We attended at the request of the police.”
One eyewitness told The Courier: “It’s an open office. The police were there within minutes.”
The Job Centre re-opened in the afternoon.
A police spokeswoman said: “Police in Kirkcaldy attended an incident at the Kirkcaldy Job Centre.
“A man was restrained by security staff and was subsequently detained.
“The woman was taken to the Victoria Hospital by the Scottish Ambulance Service for treatment to a head injury.
“A report will be sent to the Procurator Fiscal.”
A Department of Work and Pensions (DWP) spokeswoman said: “Violent behaviour towards our staff is completely unacceptable and thankfully is incredibly rare. We will be working closely with the police on this incident.”