An investigation is under way after a fire broke out at Lancaster police station on Saturday evening.
Fire crews from Lancaster, Morecambe, Carnforth, Bolton-le-Sands, Hornby, Fulwood, Preston, Silverdale, Preesall, Cumbria and Hyndburn were called to the scene after the alarm was raised at around 9pm.
The blaze started in an office on the third floor of the four-storey building.
The fire was extinguished at around 11.45pm.
The fire service said there was extensive smoke damage and concerns about the roof. Staff were evacuated and there were no injuries.
Neighbouring roads were closed to traffic and diversions put in place.