At least three dead and more injured after Amtrak train carrying students derails in Missouri

Three people have died and more are injured after a passenger train derailed in Missouri in the US, after hitting a dump truck that was blocking a public crossing.

The Amtrak train, which was travelling from Los Angeles to Chicago on Monday, hit the truck on an "uncontrolled crossing" near Mendon at 1.42pm local time.

The collision caused seven out of the Southwest Chief's eight cars to derail, said police.

Officials say they do not yet know how many were injured but 243 passengers, including high school students, and 12 members of staff were on the train at the time.

Three people died - two on the train and one inside the truck.

Missouri State Highway Patrol said there were no lights on the uncontrolled crossing where the collision happened, but this is commonplace on rural crossings.

Eight helicopters are taking people from the scene due to its remote location. It took first responders 20 minutes to arrive, police said.

Helicopter video from the scene showed train carriages on their side as emergency responders used ladders to climb into one of them. Medical helicopters were seen parked nearby waiting to transport patients.

Three passengers were taken to University Hospital in Columbia, hospital spokesperson Eric Maze said. He did not have information on their conditions.

Passengers on the train included high school students from Pleasant Ridge High School in Easton, Kansas, who were headed to a Future Business Leaders of America conference in Chicago, Superintendent Tim Beying told The Kansas City Star.

The Southwest Chief takes about two days to travel from Los Angeles to Chicago. Mendon, with a population of about 160, is about 84 miles (135 kilometers) northeast of Kansas City.