Seven people were killed and 39 others injured after a commuter-van exploded in Northeast China's Heilongjiang Province on Friday, local authorities said.

The commuter-van from a mine company in Shuangyashan city exploded around 6:30 am in the district of Lingdong, a city government spokesman said at a press conference in the afternoon.

The explosion affected a coach on the opposite lane. An earlier report said a collision between the commuter-van and the coach led to the explosion, which proved to be inaccurate.

There were 52 passengers aboard the two vehicles, said the spokesman.

The injured have been sent to two hospitals. Their conditions are not available.

The Zhongxing Mineral Industry Company, which owns the commuter-van, is a private enterprise.

An investigation into the cause of the accident is under way. China Central Television quoted witnesses saying there was detonator on the commuter-van when the accident happened. However, this has not been confirmed by authorities.