A raging wildfire in northern California has killed two firefighters and forced tens of thousands of people to flee their homes.

Fire Officials say the fires in Shasta county are being sucked up by strong winds to form "fire tornados" that are uprooting trees and overturning cars.

The fires have destroyed at least 500 structures and are threatening thousands of homes.

Firefighters are battling the blaze, which is only 5% contained so far.

The wildfire, which has been named the Carr fire, began on Monday and has scorched over 48,000 acres (194 sq km) of land ‑ an area larger than the city of San Francisco.

About 37,000 residents have been forced to leave the area.