The death toll of a bus and train collision in Heilongjiang province has increased to 10 people, Heihe information office said on Tuesday.

The cause of the accident is still under investigation.

Ten people were killed and 37 injured when a train collided with the bus on Monday in Heihe, Heilongjiang province. Chen Hao / for China Daily

According to Li Qing, head of Heihe Railway Group, the bus is suspected to have been overloaded. The injured driver is being investigated.

Li said the train watcher sent the message too late that the guard assigned to warn vehicles had failed to arrive at the crossing track in time.

Thirty-seven people were injured in the accident.

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9 killed when bus, train collide