San Francisco, Aug 16 (IANS): Smoke from several wildfires burning in Southern California has resulted in unhealthy air quality across the region, authorities said.

According to the South Coast Air Quality Management District, smoke from the Lake Fire and Ranch 2 Fire currently burning in the region has caused unhealthy air quality throughout large parts of Los Angeles County, including Santa Clarita Valley, San Fernando Valley, Pomona-Walnut Valley and San Gabriel Valley, reports Xinhua news agency.

Firefighters are racing to contain several fast-moving wildfires in Southern California amid heatwave.

The Lake Fire, burning near Lake Hughes north of Los Angeles, has charred more than 14,000 acres at 12 per cent containment as of Saturday morning, according to the California Department of Forestry and Fire Protection.

The Lake Fire started on August 12.

The Ranch 2 Fire, burning in the Angeles National Forest north of Azusa, has scorched 1,400 acres and was only 3 per cent contained as of Saturday morning.

The fire was first reported on August 13.

"It is difficult to tell where smoke, ash or soot from a fire will go, or how winds will affect the level of these particles in the air, so we ask everyone to remember that smoke and ash can be harmful to health, even for people who are healthy," Muntu Davis, Health Officer for Los Angeles County, said on Saturday.

"If you can see smoke, soot, or ash, or you can smell smoke, pay attention to your immediate environment and take precautions to safeguard your health.

"These precautions are particularly important for children, older adults, and people with heart or lung diseases," he added.

Los Angeles County public health officials urged local residents to avoid unnecessary outdoor exposure and limit physical exertion, such as exercise, as precautions.