LOS ANGELES, Oct. 10 (Xinhua) -- U.S. Southern California's primary electricity company shut off power to more than 21,000 customers on Thursday in high fire risk areas, as several wildfires erupted in the region amid powerful Santa Ana winds.

More than 21,000 customers in Los Angeles, San Bernardino, Ventura and Kern counties were affected by the Public Safety Power Shutoff (PSPS), said electricity supply company Southern California Edison on Thursday midnight.

Approximately 233,000 customers in parts of nine counties in Southern California are also under the PSPS consideration, according to the company.

There are between two and three people for each electrical customer, local media reported.

"Turning off our customers' power is not something we take lightly, but PSPS events are one of the ways we can better ensure the safety of the public, our customers, and our employees," the company said.

Power lines are to blame for igniting several massive wildfires in recent years in California State. The devastating wildfire in 2017, dubbed the Thomas Fire, was started by power lines coming into contact in high winds, said officials in March after a more-than-one-year probe.

Southern California Edison and another major utility company in California, Pacific Gas and Electric Co., have been hit with lawsuits from wildfire victims about their liability for past wildfires in recent years.

Pacific Gas and Electric Co. cut power to hundreds of thousands of people on Wednesday in Northern California as a precaution against sparking wildfires amid windy and dry weather conditions.

The utility declared bankruptcy in January to manage the legal costs after it was found responsible for some major wildfires, including the Camp Fire, the deadliest and most destructive wildfire in California history, which killed at least 86 people, and destroyed 14,000 residences last year.

At least three wildfires broke out in Southern California on Thursday afternoon fanned by powerful winds. According to the Riverside County Fire Department, the Reche fire, a fast-moving fire, has burned 400 acres near Moreno Valley in the county.

In another wildfire, the Sandalwood fire, 74 structures have been destroyed and five received moderate damage.

At least one commercial building was destroyed by the Saddleridge fire and evacuation orders were issued, according to the Los Angeles Fire Department.

A red flag warning will be in effect through Friday evening for Southern California, according to the National Weather Service.

"A moderate to strong Santa Ana wind event will continue to bring dangerous fire weather conditions to most of Los Angeles and Ventura Counties through late Friday afternoon," said the agency on Thursday evening.

Sometimes called "devil winds," the Santa Ana winds are strong, extremely dry downslope winds that originate inland and affect coastal Southern California, and are infamous for fanning regional wildfires.

There is a chance that the red flag warning will need to be extended into Saturday, "especially for the mountains," noted the National Weather Service.

"With dry fuel conditions established, very critical fire weather conditions are expected with the potential for very rapid fire spread, long range spotting, and extreme fire behavior with any new fire ignitions," the agency said.