SONOMA, California (AP) — Rising winds fanned the California wildfires again yesterday, forcing hundreds more people to flee from their homes in the state’s fabled wine country and testing the efforts of crews who have spent days trying to corral the flames behind firebreaks.

Just a day after firefighters reported making significant progress, the winds kicked up several hours before dawn and pushed flames into the hills on the edge of Sonoma, a town of 11,000. About 400 homes were evacuated as the fires threatened Sonoma and a portion of Santa Rosa that included a retirement community that evacuated earlier this week, authorities said.

Dean Vincent Bordigioni, winemaker and proprietor at the Annadel Estate Winery, awoke at three yesterday morning with flames erupting on the ridge above his property.

“Things went to hell last night,” he said. “They’ve got a good fight going on.”

Nearly a week after the blazes began, the fire zone had swollen to an area as long as 100 miles on a side. The flames have left at least 35 people dead and destroyed at least 5,700 homes and businesses, making them the deadliest and most destructive group of wildfires California has ever seen.

Yesterday an unknown number of additional structures burned down in a rural area, said Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection.

Judy Guttridge, who was evacuating for the second time this week, said her daughter saw flames advancing over the side of a hill around the same time Bordigioni did and told the family to get out.

“I have good insurance,” she said. “All the kids, grandkids, great-grandkids are fine. I’m OK with that.”

Firefighters spent much of the last week digging defence lines to keep the flames from spreading. On Friday, they tried to fortify the edge of Sonoma using bulldozers and other heavy equipment.

But if winds push the flames over that barrier, neighbourhoods, including some of the town’s costliest homes, were in the path along with a historic central plaza built centuries ago when the area was under Spanish rule.

The renewed strength of the winds was “testing the work that we accomplished”, Berlant said. The greatest risk was that winds would blow embers across the firebreaks and ignite new blazes.

Winds gusting up to 40 mph were expected to continue throughout the day and into the evening.