A human-caused wildfire is burning on Nanaimo's Mount Benson, about seven kilometres west of the city.

However, officials say no homes or structures are threatened by the fire.

The fire, fuelled by warm temperatures and a steady wind, broke out Saturday afternoon and quickly grew to four hectares according to the B.C. Wildfire Management Branch.

Officials say 13 firefighters, two helicopters and air tankers are currently working the area where the fire danger is rated as high.

Crews are also asking recreational boaters to avoid water pickup locations so the firefighting aircraft can safely complete their work.

The wildfire management branch says the fire is human caused and currently under investigation to determine its specific cause.

In the meantime it is reminding the public only small campfires smaller than 0.5 metres tall by 0.5 metres wide are allowed within the boundaries of the Coastal Fire Centre.

It is also asking people to be careful with any activity that could lead to a forest fire.

"Cigarettes should be extinguished carefully in water, and vehicles should avoid parking or driving through tall weeds and grasses," it said in a statement.

The B.C. Wildfire Management Branch says a wildfire burning seven kilometres west of Nanaimo was human-caused. (B.C. Wildfire Management Branch)

Google Map: Mount Benson, Nanaimo, B.C.