In Pictures: Wildfires continue to rage across US’s California | US & Canada

Firefighters in Southern California on Tuesday reported little progress against two explosive, windswept forest fires that forced the evacuation of tens of thousands of U.S. residents.

Howling Santa Ana winds blowing hot, dry air from the desert had put much of the fire-ravaged state under red flag warnings and helped quickly spread two flames in Orange County that broke out on Monday.

More than 750 firefighters using 14 helicopters were able to contain just 5 percent of the Silverado fire, which rose from 2,900 acres overnight to 4,500 acres (11,200 acres) late Monday, the Orange County Fire Authority (OCFA) said.

Two firefighters were seriously injured while fighting the fire, with much of their bodies showing second and third degree burns, according to the OCFA.

The fire in the foothills of the Santa Ana Mountains south of Los Angeles prompted officials to order more than 90,000 residents to evacuate their homes in and around the city of Irvine on Monday.

The other Orange County fire, the Blue Ridge Fire, which later broke out near Yorba Linda, also spread quickly overnight, charring 6,150 hectares (15,200 acres) by Tuesday morning, OCFA said.

Forest fires this year devastated California and scorched more than 16,500 square kilometers – the equivalent of the land mass of the state of Hawaii – since the beginning of the year. 31 people died and thousands of houses were destroyed.