Firefighters are still battling hundreds of wildfires moving across areas of the western U.S. state of California.

Nearly 2,000 fires have burned in hot, dry conditions in California since June 20. Officials say lightning caused most of the fires.

On Thursday, a volunteer firefighter collapsed and died while fighting a blaze, and health officials have raised concerns over poor air quality.

Firefighters are working to contain a blaze that has burned more than 20,000 hectares near the scenic coastal area of Big Sur in central California. Authorities ordered more evacuations in the area on Wednesday.

Last week, President George Bush declared a state of emergency for California and ordered federal aid to assist in firefighting efforts.

California is often hit by wildfires due to its arid climate and hot, dry winds. Last year, fires destroyed more than 200,000 hectares and some 2,000 homes in southern California.

Some information for this report was provided by AP and Reuters.