UPDATE: ONE home has been destroyed and another damaged in out-of-control grass fires in Melbourne's northern suburbs.
A CFA spokeswoman said a large fire was affecting different areas.
"One house has been destroyed and one has been damaged in the Donnybrook-Kalkallo fire,'' the spokeswoman said.
A watch and act alert is in place for residents in parts of Epping, Lalor and Thomastown.
Victoria's Fire Services Commissioner Craig Lapsley said an undetermined number of homes are believed to have been lost.
Epping North residents started to flee their homes earlier this afternoon, seeking refuge in shopping centres and community hubs, as a fast-moving grass fire closed in.
Fire crews stopped the grassfire on its western front at Somerton and are now concentrating on the eastern flank, which has grown to more than 1900ha.
More than 450 firefighters in 90 strike teams are battling the fire with six helicopters and five planes water-bombing it.
There are more than 100 CFA and MFB fire vehicles at the scene as well as 11 aircraft.Read more on the Herald Sun