A rapidly spreading wildfire in Southern California, known as the Hughes Fire, exploded to nearly 10,200 acres as of Thursday morning, crossing parts of Interstate 5 and sending heavy smoke billowing across the area.

Following arrests of alleged firefighter impersonators, officials say two more people have been taken into custody for using fake passes to unlawfully enter a fire evacuation zone.

By David Swanson and Daniel Trotta CASTAIC, California (Reuters) -A new wildfire that broke out north of Los Angeles on Wednesday rapidly spread to more than 9,400 acres (38 square km), fueled by strong winds and dry brush,

Firefighters in Southern California conducted another fierce wildfire fight on Wednesday and into Thursday morning.

Offramps along Interstate 5, a major north-south artery, were closed as flames raced along hilltops and down into rugged canyons.

As critical fire weather continues to strike in Southern California, crews are also tasked with preparing for a storm expected this weekend that could trigger mudslides in burn scar areas.

A brush fire erupted amid powerful winds Wednesday afternoon in the Castaic area in the northern region of Los Angeles County, spreading quickly to 10,176 acres near the freeway, officials said.

All lanes of the I-5 Freeway through the Grapevine will be closed for an unknown duration, according to the California Highway Patrol.

The fire threat remains critical in Southern California, where thousands of residents were under evacuation orders Wednesday as fire crews battled the out-of-control Hughes Fire near Castaic, a suburb in the foothills and mountains of northern Los Angeles County.

A new wildfire that broke out north of Los Angeles rapidly spread to more than 32 square kilometres, fuelled by strong winds and dry brush, forcing mandatory evacuation orders for more than 19 000 people.

An explosive new wildfire erupted north of Los Angeles on Wednesday, forcing tens of thousands of people to evacuate their homes and setting nerves jangling in an area still reeling from two deadly blazes.