More than 2500 firefighters are struggling to tackle several wildfires which are burning to the north of Los Angeles in the United States.
The fires in California began six days ago and have been fuelled by hot weather and dense, dry brush, the BBC reports.
The blaze doubled in size in a day to spread over 347 square kilometres of Angeles National Forest.
About 12,000 buildings and key communications masts are under threat, and officials say the fire could easily double again over the coming days.
The fire is only 5% contained and is likely to burn for many more days before it is brought under control. A huge plume of smoke is visible over the city of Los Angeles.
Two firefighters died on Sunday after their vehicle was overrun by flames.
California Governor Arnold Schwarzenegger has declared a state of emergency and urged people to comply with evacuation orders.
More than 10,000 residents have fled and 6,600 homes are under mandatory orders to evacuate.
At least 18 houses have been destroyed, although that number was expected to grow, officials said.
Wildfires are a feature of the Californian summer, but it is unusual for them to break out so close to major population centres.