Police said that a security guard on board a bank vehicle shot and killed the driver of an armored vehicle on Monday and then committed suicide in Handan city, Hebei province.

Local police said in its micro blog that the guard had "a dispute" with the driver, without elaborating.

The killing, which happened near a bank in the city, initially prompted suspicions that the bank vehicle had been robbed.

But police said that nothing was missing from the vehicle.

The case is being investigated.