Five people were killed by the crash of a medical ambulance plane carrying them in the western US state of Nevada.

Remsa Health Medical Ambulance Services said its plane crashed on Friday evening, carrying a nurse, a paramedic, a patient and a family member, in addition to the pilot.

It said the plane disappeared from radar on Friday evening outside the arid town of Stadejkoch near Nevada's border with California.

She pointed out that the plane crashed as a large snowstorm hit the west coast of the United States.

About 100,000 people in California were without electricity on Saturday evening, according to specialist PowerOutage.us, and several major roads have become impassable due to ice and snow, including parts of Interstate 5 linking Mexico, California, the Pacific Northwest and Canada.