A delivery truck has struck a bus carrying American students in northern California, killing ten people and injuring at least 30.

Five students, three chaperones and the drivers of bus and FedEx truck were killed, according to the California Highway Patrol and Humboldt State University, which was to host the students' visit.
The tenth fatality was confirmed by a CHP spokeswoman early today as a chaperone on the tour bus.
"All of a sudden I heard people screaming," 17-year-old Jonathan Gutierrez told NBC's 'Today' show, saying he had been asleep before the impact.
Mr Gutierrez, who suffered cuts on his face, said the aisle of the tour bus filled with smoke and students broke windows to escape.

"It was a very surreal moment," he said.

More than 30 people were hurt after the driver of the FedEx truck lost control, it crashed through a divider on Interstate 5, side-swiped a car and smashed head-on into the bus yesterday evening, CHP spokeswoman Tracy Hoover said.             

"They are traumatised, absolutely," Ms Hoover said of the injured.

"Most of them have scratches, cuts, burns, contusions and lacerations - a magnitude of injuries."

About 34 people were taken by air and land ambulances to hospitals in varying conditions, police said.

No one in the car that was side-swiped was killed, though the driver was sent to hospital with unspecified injuries.

Apart from the driver, the bus was carrying between 44 and 48 students and several chaperones to the university for a campus tour, CHP spokeswoman Lacey Heitman said.
The crash took place near the city of Orland, 150km north of Sacramento.

The students, travelling from Los Angeles-area high schools, were part of a programme Humboldt State said "brings low-income and first-generation prospective college students from the Los Angeles and San Francisco areas to HSU's campus."

Pictures from the scene showed the bus reduced to a burned-out chassis resting sideways across the highway. 

Yellow tarps appeared to be draped over bodies in the wreckage.

Ms Hoover described hunks of twisted metal and broken glass and said flames had roared through the vehicles.

"The big rig and the bus were both engulfed in flames. Youare talking about two vehicles that are destroyed. There is hardly anything left of the truck," Hoover said.
Two other charter buses that were also carrying students to Humboldt - one from the Los Angeles area and one from the Fresno area - had arrived safely, the university said.
Bonnie Kourvelas, a spokeswoman for FedEx Corp, said the company was aware that one of its trucks was involved in the crash.
"We are cooperating fully with authorities as they investigate," she said.
Some of the students were from Manual Arts Senior High School, Robert F Kennedy Community Schools and Banning High School, said Los Angeles Unified School District spokesman Tom Waldman.
Humboldt State President Rollin Richmond said students fromsouthern California had been traveling to the college campus fora spring preview event on Friday.
"Our hearts go out to those who have been affected, and we are here to support them, and their families, in any way possible," he said in a written statement.
The students were to visit the campus for two days and stay in residence halls, the university said.