A train has ploughed into a big-rig truck stopped on the tracks outside the northern Italian city of Turin, killing at least two people and injuring 18 others, authorities said.

The Italian news agency ANSA said the first fatality was the engineer of the train, which smashed into the truck near the town of Caluso late on Wednesday on a run from Turin to the suburb of Ivrea.

Later, one of two critically injured people who were flown by helicopter to a hospital died, ANSA said.

One of the less seriously injured was reported to be a crew member, while the others were passengers. Ambulance dispatches said a total of 18 people were injured, most of them not critically.

The truck driver escaped injury, ANSA said. The rig, which carried Lithuania licence plates, was headed to a warehouse not far away, ANSA said. The truck's cargo was not immediately known.

The Rfi regional railroad said the railway barrier had lowered properly before the train's approach but for reasons unknown the truck smashed through the barrier and ended up on the tracks.

The crash derailed three train cars.

ANSA quoted a young woman who broke her leg in the crash as saying she felt as if she was being pushed from behind, then fell. The passenger, who was not identified in the report, said she feared she would die, describing the scene as terrible.

Rescuers were searching the wreckage looking for any trapped passengers.