At least 13 dead in California bus crash

At least 13 people have died and 31 others were injured when a tour bus crashed into the back of a tractor-trailer in southern California.

The bus was said to have been returning from a casino trip when it crashed on a highway near the city of Palm Springs at around 5am in the morning.

The bus driver was among those killed.

California Highway Patrol Chief Jim Abele said it was one of the worst crashes he had seen.

"In almost 35 years I've never been to a crash where there's been 13 confirmed. So it's tough. It's tough for all of us."

Pictures from the scene showed the front window of the bus ripped off and the front section of the vehicle badly crushed.

Emergency services were using metal ladders to reach the inside of the coach and remove casualties.

Five people of the injured are said to be in a critical condition and a further six have serious injuries.

At least 17 others reportedly suffered minor injuries.

Several survivors reported most of the passengers, all of whom were adults, were sleeping at the time of the crash.

The cause of the crash was not immediately clear but the bus was travelling "significantly faster" than the tractor-trailer.

The National Transportation Safety Board said it will investigate the crash.