At least 31 people are now confirmed dead in the wildfires sweeping northern California.

Officials say progress in battling the blazes is being made, but fears are high the death toll could surge. Hundreds of people are still missing.

In the town Calistoga, immediately in the line of fire, the mayor warned residents on Thursday that anyone refusing to evacuate would be left to fend for themselves.

“This is a mandatory evacuation. Your presence in Calistoga is not welcome if you are not a first responder. Your choice to stay, and there have been very few of them, is a distraction to our first responders. You will not be given life safety support at this point. You are on your own,” Calistoga’s Mayor, Chris Canning said.

Around 8,000 firefighters are now battling more than 20 blazes in California’s famous wine country, the deadliest in the state since 1933.

Fanned by strong winds some 3500 homes and businesses have been destroyed by flames since Sunday.

The cause of the fires is still under investigation.