By Gene Blevins

YUCAIPA, California (Reuters) - At least eight people were killed and dozens more injured when a tour bus returning to Mexico from a Southern California ski resort crashed on a mountain road and rolled over, ejecting several passengers, authorities said on Monday.

The bus driver, who survived the Sunday evening crash, reported to authorities that the motor coach had experienced a mechanical failure of some kind at the time of the accident, California Highway Patrol Sergeant Billy Rangel said.

"The bus driver is saying there were issues with the brakes," said Terri Kasinga, a spokeswoman for the California Transportation Department.

Federal transportation safety records show the California-based company identified by police as the bus operator was cited for dozens of maintenance violations over the past two years, including bald tires and brake problems as recently as July 2012.

There was no immediate indication that alcohol, drugs or road conditions were factors in the crash, which occurred at about 6:30 p.m. on Highway 38 near the town of Yucaipa, about 70 miles east of Los Angeles, police said.

The chartered bus was carrying a group of people home from a ski outing in California's Big Bear Lake resort area back to Tijuana, Mexico, when it struck a car from behind on the way down the mountain and careened out of control, Rangel said.

The motor coach then rolled over and slammed into a pickup truck, throwing several passengers from the bus, he said. The pickup was crushed in the wreck.

The mangled bus came to rest right-side-up with its front tires hanging over a culvert along the shoulder of the road, and authorities were still extracting bodies from the wreckage some 19 hours after the crash, Kasinga said.

Rangel said eight people were confirmed killed and roughly 35 others were taken to hospitals with injuries, at least one of them in critical condition. The drivers of the car and pickup truck struck by the bus also survived, he said.

Investigators later determined that 39 people, including the driver, were on the bus, and all the passengers are believed to be Mexican nationals, Highway Patrol spokesman Officer Cliff Porter said.

The bus was operated by Scapadas Magicas, a tour company based in National City, California, just south of San Diego, Highway Patrol spokesman Mario Lopez said. The firm also operates in Tijuana. Continued...