Emergency services personnel survey the scene after the derailment of an Amtrak train in California's Central Valley on Monday.

Hanford, California - Two carriages and the locomotive of an Amtrak train carrying 169 passengers derailed on Monday after colliding with a big rig truck in California's Central Valley, authorities said.

Twenty passengers suffered minor to moderate injuries.

The crash occurred when the driver of the big rig carrying cotton trash failed to yield and hit the train, authorities said. The impact pushed the two passenger carriages and the locomotive off the tracks south of Hanford, a farming town.

The train travelled about 180m after the collision before hitting a switchback and derailing, according to California Patrol Officer Scott Harris.

The crash occurred at a crossing that was equipped with control gates, Putnam said.

The injuries to passengers were described as bumps, bruises, scrapes and possibly broken bones by Kings County Assistant Sheriff Dave Putnam.

Eight of the injured passengers were taken to Adventist Medical Centre in Hanford and five more were en route, said hospital spokesperson Christine Pickering.

Four additional injured passengers were taken to nearby Adventist Medical Centre in Selma.

The train was on its way from Oakland to Bakersfield, according to Amtrak. It had four rail carriages and a locomotive.

The truck driver suffered minor injuries, according to California Highway Patrol spokesperson Jerry Pierce. The CHP will investigate the crash. - Sapa-AP