A fugitive former police officer accused of a revenge-fuelled killing spree barricaded himself in a cabin in the mountains northeast of Los Angeles tonight after a gunfight with police that left at least two officers wounded, police said.
The San Bernardino County Sheriff's Department said Christopher Dorner, 33, opened fire as police closed in on him.
An intensive manhunt for Mr Dorner has been under way for six days.
The county fire department said one of the wounded officers had been flown by helicopter to a hospital.
The Los Angeles Times reported that days ago Mr Dorner broke into another cabin in the ski resort community of Big Bear Lake, tied up a couple and held them hostage until midday today.
He then fled in a stolen vehicle.
A state game warden on the lookout for the vehicle spotted it and he exchanged fire with Mr Dorner. Andrew Hughan, a spokesman for the California Fish and Wildlife Department, said the warden was unharmed.
Mr Dorner later abandoned the vehicle and fled into the forest where he broke into the cabin from which he battled police.
Last Thursday, Mr Dorner shot and killed one police officer and wounded another at a traffic light in Riverside, California, about 100km east of Los Angeles, according to police.
A former officer in the US Navy, he is also suspected of having exchanged gunfire with police in nearby Corona. One officer was wounded in that shoot out.
He was named a suspect last Wednesday in the killings of a campus security officer and his fiancee, the daughter of a retired Los Angeles Police Department captain.
In a manifesto posted on his Facebook page last week, Mr Dorner blamed the captain for his 2008 dismissal from the LAPD.
In the rambling statement, Mr Dorner claimed that he had been wrongly fired from his job, and he vowed to take revenge through "unconventional and asymmetrical warfare" on police officers and their families.