Flames overtake a structure in the Napa wine region on October 9.

(CNN)New evacuations were ordered Tuesday evening as more than a dozen wildfires raged across Northern California, with the largest ones killing at least 17 people as they scorched the state’s famous wine country.

The largest of the deadly fires were burning in Sonoma, Napa and Mendocino counties, with flames ripping through the lush, picturesque landscape.

Officials in the city of Santa Rosa and Sonoma County called for the evacuations of five more areas Tuesday evening. Already, 20,000 people had been ordered to leave the area and other parts of Northern California.

It is too early to tell whether any of the wildfires were started by humans, said Ken Pimlott, director of Cal Fire. “All these fires are under investigation,” he told reporters, adding that his department was focusing on rescues and firefighting. But he said the chance the fires were caused by lightning was “fairly minimal.”

• At least 17 people have died since Sunday night, when most of the fires began. A total of 11 deaths were in Sonoma County, officials said.

• Two of those who died were in Napa County, county spokeswoman Kristi Jourdan said. They were 100-year-old Charles Rippey and his wife, Sara, 98. They died when a fire engulfed their home near the Silverado Country Club north of Napa, Jourdan said.

Two women hug as they watch houses burn in Santa Rosa on October 9.
Colby Clark, left, comforts her mother, Bonnie Trexler, after law enforcement escorted them to Trexler's home in Napa, California, to retrieve medicine and personal items on Wednesday, October 11. Trexler was one of the lucky few in her neighborhood whose home was spared. Deadly wildfires have been tearing through the state, destroying homes and businesses and prompting evacuation orders.
Photos: Wildfires blaze in California

Colby Clark, left, comforts her mother, Bonnie Trexler, after law enforcement escorted them to Trexler’s home in Napa, California, to retrieve medicine and personal items on Wednesday, October 11. Trexler was one of the lucky few in her neighborhood whose home was spared. Deadly wildfires have been tearing through the state, destroying homes and businesses and prompting evacuation orders.

Highway Patrol officers go door to door to ask Sonoma residents to evacuate their homes as a wildfire approaches on October 11.
Photos: Wildfires blaze in California
Homes are destroyed in the Coffey Park neighborhood of Santa Rosa on October 11.
Photos: Wildfires blaze in California
The sign of a Firestone store malfunctions in Santa Rosa on Tuesday, October 10.
Photos: Wildfires blaze in California
Damaged winemaking vats and tanks stand in ashes and debris at the Paradise Ridge Winery in Santa Rosa.
Photos: Wildfires blaze in California
Smoke clouds the sun from wildfires burning in Santa Rosa and Napa Valley on October 10.
Photos: Wildfires blaze in California
Mary Caughey, center in blue, reacts after finding her wedding ring in the remains of her home in Kenwood on October 10.
Photos: Wildfires blaze in California
Puddles of melted metal trail away from a burned-out car near Napa on October 10.
Photos: Wildfires blaze in California
A firefighting plane helps battle a blaze just north of Tustin on October 9.