Two people were severely injured and two others have been reported missing after an oil residue tank blast caused a fire on Sunday in Liaoning Province, firefighters said. One tank containing residual diesel oil exploded around 2:20 p.m. at a PetroChina outlet in the port city of Dalian, causing a nearby tank to burst into flames, Xinhua quoted firefighters with the city as saying. More than 300 firefighters were mobilized to put out the fire by 4:30 p.m. Four people were at the site at the time of the accident. The injured have been hospitalized, and doctors said they were both in life-threatening conditions. Environmental authorities said the nearby sea had not been polluted but some residential communities were affected by fumes. Oil barriers have been erected in the sea near the factory as a precaution, and the local government has advised nearby residents to close their windows.