Los Angeles police detectives are investigating the slaying of a man believed to be an Armenian American whose head rolled out of a plastic bag discovered by a dog off a trail below the Hollywood sign Tuesday afternoon.

Two women were hiking with the dog in the rugged hills near the 3200 block of Canyon Drive, when the dog found a plastic bag in the brush containing the head, according to law enforcement sources with knowledge of the investigation but who asked not to be identified because the investigation was still unfolding.

The sources said the head was believed to be that of an Armenian male in his 40s with salt-and-pepper hair. Police also believe that the slaying was recent based on the condition of the remains.

Sources said investigators are trying to determine whether there are additional body parts in the area. Neither the circumstances nor the cause of death were immediately known.

The case is being handled by the LAPD’s elite Robbery-Homicide Division. In addition to combing the area for evidence, investigators will seek help from the Los Angeles County coroner's office to identify the victim through dental records.

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Photo: Location where head was found. Credit: KTLA News