Alleged US cop killer's car found with weapons: reports

More than 100 police searched the snow blanketed California mountains Saturday for an ex-cop accused of three killings after his car was found nearby, reportedly with weapons and a broken axle.

Police are hunting for Christopher Dorner, a 33 year-old disgruntled former LA Police Department (LAPD) officer who had threatened to murder police in a chilling online manifesto.

The search has focused on cabins above the ski resort of Big Bear, two hours east of Los Angeles, where Dorner's burnt-out pickup truck was found in nearby woods.

Police believe Dorner abandoned the truck when its axle broke, CBS News and CNN reported Saturday, citing anonymous sources.

An arsenal of weapons and survival gear was found inside the truck, which Dorner set ablaze Thursday morning, the networks reported.

Police apparently also want to make sure that Dorner does not slip into Mexico: at San Ysidro, the world's busiest land border, federal agents wearing body armor and cradling rifles kept a close eye on southbound vehicles, and only two of the four traffic lanes were open at the border crossing.

Law enforcement officers in San Diego County remained on heightened alert, but reported no possible sightings of Dorner, who was fired by the Los Angeles Police Department five years ago.

"We're at regular staffing at this point, but we have other special units that are monitoring what's going on and if things come up, they'll be able to respond," said Scott Amos, a spokesman with the San Diego County Sheriff's Department.

The hunt for Dorner, who police describe as "armed and extremely dangerous," has extended into the neighboring states of Arizona and Nevada, CNN reported.

California authorities launched the manhunt Thursday for Dorner, a naval reservist suspected of killing a couple on February 3 then ambushing two policemen early Thursday, killing one.

He also injured another officer in a separate incident.

In an Internet manifesto threatening police and their families, Dorner pledged to "bring unconventional and asymmetrical warfare to those in LAPD uniform whether on or off duty."

The LAPD, backed by agencies including the Federal Bureau of Investigation (FBI), is protecting over 40 possible targets, some of them identified in Dorner's rambling online manifesto.