'Too late to leave': Residents warned to take shelter as grass fire burns out-of-control north-west of Melbourne

A grassfire burning across multiple suburbs on Melbourne's north-western fringe was growing quickly after a wind change this afternoon.

The emergency-level blaze near Sunbury, about 40 kilometres from the CBD, had already burned through more than 250 hectares.

Residents in Beveridge, Bolinda, Clarkefield, Darraweit Guim, Mickleham, Oaklands Junction, Sunbury and Wildwood were told it was too late to leave and to take shelter immediately.

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"The safest option is to take shelter indoors immediately. Do not get in the car and drive," a VicEmergency warning states.

"It is safer to stay where you are."

The CFA said it was aware of reports of a caravan ablaze near the fireground.

A wind change shifted the flames in a north-easterly direction towards Old Sydney Road, Mickleham.

"If you are in Mickleham on Donnybrook Road or Mandalay Estate, Beveridge be prepared to walk two streets back," the CFA advised.

An earlier warning noted the fire was travelling in an easterly direction towards Boggy Rate Road.

Authorities were concerned an imminent wind change could worsen conditions.

Multiple firetrucks were responding to the grass fire, along with water aircraft.

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