Scant progress reported against two new Southern California wildfires

Oct 27 (Reuters) - Firefighters in Southern California on Tuesday made little headway against two explosive, wind-whipped wildfires that forced the evacuations of tens of thousands of residents and badly injured two crew members on the front lines.

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 blazes in Orange County that erupted on Monday.

While winds are likely to remain strong at a steady 20 to 25 miles per hour (32 to 40 kph) in the county for much of the day, the National Weather Service predicts they will abate by evening and remain light for at least the next two days.

More than 750 firefighters using 14 helicopters managed to contain only 5% of the Silverado fire, which grew overnight to 11,200 acres (4,500 hectares) from 7,200 acres (2,900 hectares) late on Monday, the Orange County Fire Authority said.

Two firefighters were critically injured fighting the blaze, with second and third degree burns over much of the bodies, the OCFA said.

The blaze, which was not immediately blamed for any property loss, may have been started by equipment owned by Southern California Edison, the utility company said.

“It appears that a lashing wire attached to a telecommunications line may have contacted SCE’s power line above it, possibly starting the fire,” a company spokesman said.

The incident is being investigated, he added.

As a precautionary measure, the utility said on Tuesday that it had cut power to nearly 19,000 homes and businesses.

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

The Irvine Unified School District closed schools for the day.

A second Orange County blaze, the Blueridge fire, later broke out near Yorba Linda and has charred roughly 8,000 acres (3,200 hectares) and damaged 10 homes, OCFA said.

Authorities late on Monday issued evacuation orders to at least 1,170 homes because of that blaze.

Wildfires this year have ravaged California, scorching more than 6,400 square miles (16,500 square kilometers) - equivalent to the land mass of the state of Hawaii - since the start of the year, with thousands of homes destroyed and 31 lives lost.

Reporting by Peter Szekely in New York; Editing by Giles Elgood