Deadly wind-driven brush fires roared out of the foothills and canyons on the northern fringe of Los Angeles on Monday, destroying dozens of homes and threatening hundreds of more dwellings.

In Southern California's first big wildfires of the season, a homeless man was found dead with his dog beneath a highway overpass swept by flames, authorities said.

Another person was killed in a collision on a freeway engulfed in smoke as police scrambled to shut down the road.

Late in the day, California Gov. Arnold Schwarzenegger declared a state of emergency in Los Angeles and Ventura counties, putting additional state resources at the disposal of local fire departments.

The first of two blazes erupted early on Sunday on the edge of the Angeles National Forest and by midday on Monday had charred roughly 5,000 acres of tinder-dry brush and chaparral in the northeast corner of the San Fernando Valley.

Authorities ordered the evacuation of about 1,200 residents from some 450 homes threatened by flames and embers fanned by gale-force Santa Ana gusts blowing in from the high desert, as smoke billowed into the air.

A separate brush fire flared on Monday in the foothills to the west and quickly consumed 3,000 acres, prompting the evacuation of hundreds more homes. Authorities said one flank of that blaze was threatening an area of about 1,500 homes.

'It's a very dangerous situation,' said Los Angeles County Fire Chief P. Michael Freeman.-Reuters