Los Angeles  - Thousands more people were evacuated from their homes in Los Angeles County on Sunday as a major wildfire spread its flames over a wider area.

The so-called Station Fire was threatening more than 10,000 homes, state fire officials said.

The flames in the Los Angeles National Forest sent a huge plume of smoke into the air over the city and could be seen for miles, while authorities warned of poor air quality.

California Governor Arnold Schwarzenegger visited the base of operations for the more than 1,800 firefighters battling the blaze and noted the difficult conditions hindering firefighting, including temperatures near 35 degrees Celsius and dry brush that had not burned for years. On Friday, Schwarzenegger had declared a state of emergency to speed relief efforts.

The 14,000 hectare blaze was only 5 per cent contained early Sunday, state fire officials said. Three homes had been destroyed.

Elsewhere in the state, 100 homes were threatened and one had been destroyed in a 2,500 hectare blaze near Pinnacles National Monument in Monterey County that was 80 per cent contained, and 50 homes were threatened by a 1,700 hectare blaze in Yosemite National Park that was 50 per cent contained. (dpa)