At least five people have died and many are injured after a tour bus crashed on a Californian highway.

California Highway Patrol Officer Moi Onsurez said the crash happened shortly before 3:30am, local time, on State Route 99.

It happened between the cities of Atwater and Livingston, as the bus headed from Southern California to Sacramento.

Photos and video show the unmarked white bus crashed into the pole of a highway exit sign.

The sign appears to have torn through the middle of the vehicle. Emergency workers climbed in through the windows.

Mr Onsurez said the bus was carrying about 30 people.

Officials told NBC News that at least five people had been killed.

The northbound lanes of the freeway are closed during an investigation.

Atwater is a city of 28,000 people in Merced County, about 65 miles northwest of Fresno.