Fire destroys Onslow council offices

A suspicious fire has caused millions of dollars damage to the Shire of Ashburton offices in Onslow overnight.

Emergency services were called about 7.15pm.

A police spokeswoman said the building was gutted and the damage bill was estimated at several million dollars.

Shire of Ashburton acting chief executive Frank Ludovico told ABC Radio staff would be relocated to a temporary office.

"I think the first thing we need to do is have a chat to staff and look after them," he said.

"The multiple purpose centre that we built for cyclones and evacuations and those sorts of things, we might need to use that as a temporary office."

Police are investigating the incident.