Explosions at a PetroChina refinery in northeastern China has left two people injured and another two missing, the official Xinhua news agency said on Sunday.

The blasts occurred when two tanks containing residual diesel oil exploded on Sunday afternoon at the PetroChina Dalian refinery, Xinhua said. The refinery belongs to Dalian Petrochemical, a unit of PetroChina.

The injured were rushed to hospital for treatment and the fire was put out by the late afternoon, Xinhua said.

The Dalian refinery has three crude distillation units with total crude processing capacity of 410,000 barrels per day.

A PetroChina spokesman confirmed an accident had taken place but declined to give more details.