A pair of massive wildfires fuelled by powerful winds raged dangerously close to Los Angeles Monday evening, burning through homes, industrial buildings and leaving at least two people dead.

As fire crews struggled to contain a massive blaze in the San Fernando Valley on Monday morning, another wildfire fire was sparked to the west in the rugged terrain near the Porter Ranch area.

Fire crews weren't sure how many homes were imperiled by the second, newer fire, but by Monday evening, at least 10 houses had been destroyed, The Associated Press reported.

As officials worked to warn residents in areas up to 40 kilometres away, heavy smoke darkened the horizon and some Porter Ranch residents were blocked from driving into a gated community.

Instead, people parked their vehicles and grabbed what they could, including pillows, suitcases and even paintings.

Los Angeles County Fire Chief P. Michael Freeman urged people to flee their homes because of the fire's rapid advance.

"You may not be able to even outrun this fire," Freeman said.

While the larger of the two fires has destroyed close to 40 mobile homes, it also claimed its first fatality Monday.

The death occurred close to the steep valleys of the Angeles National forest, officials said, adding that the victim appeared to be a transient living in a small shelter.

A second person also died in a head-on a collision after flames forced police closed down the 118 Freeway. TV news reports showed video of drivers pulling u-turns on road ways and driving against traffic.

On Sunday, the fire forced the evacuation of nearly 1,200 people from Lopez Canyon to nearby San Fernando High School, officials said.

The first fire, which is burning about 35 kilometres north of downtown Los Angeles, broke out Sunday around 2 a.m. local time and was about 20 per cent contained late Sunday night.

But the situation grew more serious Monday.

By the afternoon, the fire was about 5 per cent contained and more than 1000 firefighters and emergency personnel were on the scene.

"The Santa Ana winds did flare up around 4 a.m. this morning in a violent eruption," L.A. County Fire Department spokesman Frank Guarrido told Â鶹´«Ã½net Monday.

He added that the powerful winds, which were gusting at more than 110 km/h, have grounded smaller helicopters which were battling the flames.

The fire department has called in more water-dumping aircraft, including two from Canada.

"Fortunately, the call was made last night not to let those people back in, so we did not have to re-evacuate," said Guarrido.

As a precaution, emergency medical personnel also transported eight patients on ventilators, including six newborn babies, from Olive View-UCLA Medical Center in the San Fernando Valley to other hospitals.

About 180 patients were left in the hospital.

The reignited fire destroyed more than 1,500 acres Monday morning after burning through more than 2,000 acres of the Angeles National Forest on Sunday, Guarrido said.

He added that flames have been burning in a southerly direction and lead to the closure of Interstate 210.

"It has burned right up to it," Guarrido said.

A fire weather watch has been declared for Monday and Tuesday for Southern California in anticipation of the high winds.

Many locals own horses and other livestock, which were also evacuated to a safe area, L.A. County Fire Department spokesperson Ron Haralson said on CTV's Canada AM.

Haralson said the fire department increases its staff every year around this time in advance of the powerful Santa Ana winds.

Haralson said officials do not yet know the cause of the fire. Investigators are on the scene, attempting to determine the fire's "point of origin," he said.

In the meantime, firefighters in northern California are battling an out-of-control blaze on the east side of Angel Island in San Francisco Bay.

Officials have evacuated campers from the area.

With files from The Associated Press