At least six people, including two firefighters and two children and their great-grandmother, have been killed in a wildfire that continues to rage through parts of northern California.

According to officials, the death toll reached six on Sunday after the remains of an individual were found in a burnt-out residence. They added the individual had not complied with an evacuation order.

Authorities said they were still looking for seven people after finding nine others who had been reported missing.

More than 38,000 people remained under evacuation orders on Sunday in and around Redding, a city of 90,000 people about 257km north of the state capital Sacramento.

Redding Police Sergeant Todd Cogle confirmed that three bodies discovered at a fire-ravaged home on the outskirts of Redding on Saturday were two children and their great-grandmother.

The victims identified by relatives on Facebook and in news media reports were James Roberts, five, his sister Emily, four, and their great-grandmother, Melody Bledsoe, 70.

Bledsoe’s granddaughter, Amanda Woodley, said on Facebook the elderly woman desperately put a wet blanket over the children as their home burned.

“Grandma did everything she could to save them,” Woodly wrote.

The Carr Fire, which has destroyed more than 650 structures, is the deadliest and most destructive of nearly 90 wildfires burning from Texas to Oregon. The blazes have killed four firefighters in California in a little more than two weeks.