PART-time firefighters in North Yorkshire were outraged when a prankster nailed a sign to the building that houses their engine that read "Pretend Fire Station."

And the incident, which happened sometime between 11.45am and 2pm on Thursday, is now being taken so seriously that police have launched an investigation.

The offender had obtained the old decommissioned sign for the station at Grassington and amended the wording and although the damage was minimal, the upset caused has been considerable Local station manager Ben Cairns said angrily: "Our retained firefighters are here to protect their local communities and provide a much-needed and highly regarded professional service.

"Whoever is responsible for this mindless act is showing a complete lack of respect for these firefighters and the vital service they provide."

PC Simon Crossley said: "The firefighters at the station are understandably very angry about the incident and feel insulted that someone from the local community would resort to doing such an offensive act.

"This is not simply a bad-taste prank, it is highly malicious and offensive to the retained firefighters who serve and protect local people."

Witnesses or anyone with information that could help identify the prankster, should contact PC Crossley of the Grassington Safer Neighbourhoods Team on 0845 6060 247.

Alternatively, information can be passed on anonymously to Crimestoppers on 0800 555 111.