At least four children have died after a train sliced open a school bus in southern France.

The victims of the horrific crash on Thursday at a crossing near the Spanish border were aged 13 and 13, while 18 others and the bus driver were injured.

Philippe Vignes, police chief in the Pyrenees-Orientales region, told BFM television that several children and the bus driver remained in a serious condition yesterday.

French authorities said all victims had been identified and their families notified.

The bus was carrying students aged 11 to 15 from the Christian Bourquin school in the village of Millas, near Perpignan in southern France. The school opened yesterday to offer counselling for grieving students and families.

Investigators were still working to determine the cause of the crash.

Mr Vignes said he could not say whether the railway barriers meant to stop vehicles from driving on to the tracks when a train is coming were open or closed.

“There are contradictory rumours,” he said. “We need to be very careful.”

Mr Vignes said investigators were looking into reports that the batteries in the automatic train gate system had been stolen.

National railway company SNCF said the train was carrying 25 people, including passengers and crew. All were accounted for and being offered counselling.

A spokeswoman added that the train normally travels at 50mph at that location.