By Police1 Staff

BIG BEAR, Calif. — Sources say the burned out truck belonging to murder suspect Christopher Dorner has been located, and a massive SWAT search is under way in the Big Bear Mountain Resort area east of Los Angeles, where officials say "fresh tracks" have been found.

According to the Los Angeles Times, authorities believe the tracks found near Dorner's truck belong to the fugitive, and they are in the process of combing the area.

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ABC 7 News earlier reported that a vehicle roughly matching the description of Dorner's Nissan Titan truck was discovered by investigators in the Big Bear area Thursday afternoon. The San Bernardino Sheriff's Dept. later confirmed the vehicle was Dorner's. A photo of the truck can be seen at NBC Los Angeles' website.

The discovery led to an immediate, large scale search of the area by SWAT officers, according to the Los Angeles Times. The several news helicopters flying above the area captured footage of fatigue-clad officers walking the area, their rifles drawn.

As a precaution, the local Big Bear schools have been placed on lockdown effective 12:30 p.m.

"We don't believe there is an immediate danger; we do this as a precaution for the safety of our students and staff. We don't know the duration of the lock down and will post information to our website and Facebook as we get updates on the situation," said Assistant Superintended Walter Con in a statement.

Bear Mountain Snow Resort was also closed for the day.

Read full coverage of the Dorner manhunt here.