Dozens of people in the US have been rushed to hospital after a train travelling from Los Angeles to Chicago collided with a dump truck in the state of Missouri on Monday.

At least three people were killed in the accident, police said. Two of them were on board the train, while the third was the truck driver himself.

Broadcaster CNN reports that "at least" 50 more people were injured.

"The investigation is in its preliminary stages and as more information becomes available, we will be releasing it at that time," Justin Dunn, a spokesperson for the Missouri State Highway Patrol, said at a press conference.

What happened?

Railway operator Amtrak said some 243 passengers and 12 staff were on board the Southwest Chief when it crashed into a dump truck that was blocking a railroad crossing near Mendon, Missouri.

The intersection was reportedly on a gravel road with no lights or electronic controls.

Eight carriages and two locomotives derailed as a result of the accident.

Mendon, with a population of about 160, is about 100 miles (161 kilometers) northeast of Kansas City. At least six helicopters arrived at the scene to airlift passengers to hospital.

Who was on board?

Among those on the train were 16 youths and eight adults from two Boy Scout groups who were travelling home to Wisconsin after a backcountry excursion. None of the boys were seriously injured.

Scott Armstrong, director of national media relations for the Boy Scouts of America, said the Scouts administered first aid on the scene, including to several injured passengers and the driver of the dump truck.

Also on board the train was a group of high school students from Kansas, who were headed to a Future Business Leaders of America conference in Chicago.

The Missouri collision is the second deadly train accident the US has seen in recent days. In California, three people died after a train collided with a car at a railroad crossing on Sunday.

zc/rs (AP, AFP)