Five people have been killed and several others have lost limbs after a coach veered off a Californian highway and hit a pole which almost cut the vehicle in half.

Rescuers pulled out "bags of body parts" from the survivors of the crash after the coach hit the pole of a highway exit sign head-on, Merced County Sheriff Vern Warnke said.

The pole sheared straight through the coach and was only stopped by the first rear axle "with a great impact", he added.

Emergency workers climbed in through the windows to get to trapped passengers, while others had been thrown from the coach and were lying in a ditch, Mr Warnke added.

Wreckage and debris including seat cushions, drink containers, and pillows were scattered across lanes and on the hard shoulder of State Route 99.

Around 30 people were thought to have been on board at the time of the crash.

California Highway Patrol Officer Moises Onsurez identified the driver as Mario David Vasquez from the Los Angeles area, the Merced Sun-Star reported.

The newspaper added that the 57-year-old driver was among those with major injuries and was airlifted to hospital.

The coach - which was operated by Autobuses Coordinados USA - was heading to Washington state.

The crash happened shortly before 3.30am local time between Atwater and Livingstone.

Following an inspection in April the coach was found to have three violations, including a lack of or a defective brake warning device.

The violation was not further described, and there was no indication whether each of the items had been fixed.