A former Los Angeles police officer linked to a killing spree targeting police and their families is believed to have died in a fire at a rural cabin after a massive California manhunt.

Police are awaiting forensic analysis to confirm that charred remains found inside the cabin in the wooded hills of the San Bernardino National Forest were that of 33-year-old Christopher Dorner.

Authorities including Los Angeles Mayor Antonio Villaraigosa said the man who had barricaded himself inside the cabin was almost certainly Mr Dorner.

"Almost everybody believes it is him, but at this point we're not absolutely sure," Mr Villaraigosa told CNN.

"There's a sigh of relief," Mr Villaraigosa said. He cautioned, however, that it could be "days, maybe even weeks" before there is final confirmation that Mr Dorner was dead.

Mr Dorner had been the subject of a six-day manhunt across southern California.

He is believed to have made his last stand in the cabin, where a gun battle ended in the death of a sheriff's deputy and the wounding of another deputy.

Mr Dorner is suspected of killing four people, including the deputy.

An angry manifesto posted last week on his Facebook page claimed that he had been wrongly dismissed from the Los Angeles Police Department in 2008.

He vowed to seek revenge by unleashing "unconventional and asymmetrical warfare" on officers and their families.

The Los Angeles Times reported that the climax to the manhunt began when two housekeepers encountered a man believed to have been Mr Dorner inside a vacant cabin near the ski resort community of Big Bear Lake.

They surprised the suspected fugitive, who tied them up and then took off in a purple Nissan parked near the cabin.

One of the women freed herself and called police, the newspaper reported.

State game wardens spotted the vehicle and gave chase. The suspect crashed the car, then commandeered a pick-up truck at gunpoint from another motorist, said Lieutenant Patrick Foy of the state Fish and Wildlife Department.

The suspect fired at the wardens from the window of the pick-up and one of the wardens stopped his truck and returned fire with a high-powered rifle, Mr Foy said.

He said he did not know if the suspect had been hit.

Mr Foy said officers got close enough during the chase to recognise the driver as Mr Dorner before he abandoned the truck and fled into the woods to the cabin.

During a lull in the gunfire, the cabin caught fire and was quickly engulfed in flames.

Mr Dorner's last confirmed encounter with authorities was on Thursday, when police said he ambushed two policemen at a traffic light in Riverside, about 100km east of Los Angeles. One officer was killed and the other wounded.

The former US Navy officer is also suspected of having exchanged gunfire on Thursday with police in nearby Corona. One officer was wounded.

The hunt for Mr Dorner began last Wednesday when police identified him as a suspect in the killing of a campus security officer and his fiancée, the daughter of a retired Los Angeles police captain.

In his manifesto on his Facebook page, Mr Dorner blamed the captain for his dismissal from the LAPD.

Authorities posted a $1m reward for information leading to Mr Dorner's capture, an amount they said was the largest ever offered in a Southern California criminal investigation.