2 missing after blast at refinery in NE China

Investigators still trying to identify cause of accident at Dalian plant

Two workers were seriously injured and two others were missing after an explosion and ensuing fire at an oil refinery in Dalian, Liaoning province, on Sunday.

Residents look on after two diesel tanks exploded at an oil refinery of China National Petroleum Corporation in Dalian on Sunday afternoon. The fire was extinguished at 4 pm, but smoke from the blaze raised pollution concerns among residents. Liu Debin / For China Daily

Two oil tanks with residual diesel exploded in succession at about 2:30 pm on Sunday at the Dalian plant of the China National Petroleum Corp, the country's largest oil and natural gas producer and supplier.

Heavy smoke could be seen several miles away.

According to Xinhua, hospital sources said the two injured workers were in critical condition.

Sources from the city's emergency command center said the cause of the accident is still under investigation.

The tanks, which were used to store tar and other materials, was undergoing maintenance.

Nearly 100 firefighting vehicles and more than 300 firefighters responded, and the blaze was extinguished by 4 pm.

A preliminary environmental evaluation indicates no environmental damage was caused. But residents disagree.

"With such heavy smoke, how is it possible that there's no environmental damage?" said Han Lin, who lives near the plant.

She said she worries a lot about safety as accidents occur from time to time.

"We really hope that we'll be able to move somewhere far away from the plant," Han said.

This is the sixth fire at CNPC's Dalian plant in three years.

On July 16, 2010, an oil pipe exploded at the Xingang Port and caused serious oil leakage into the Yellow Sea.

About three months later, workers were found to have caused a fire at the same oil terminal as they dismantled an oil tank that still had fuel inside.

On July 16, 2011, oil refinery equipment leaked oil and caused a fire at the plant in the Ganjingzi district, the same area as Sunday's accident. On August 29, 2011, a fire broke out in a diesel tank there.

The day after the fourth fire, Jiang Fan, the general manager of the Dalian plant, was removed from his post.

In November 2011, the State Council said that the four accidents were caused by human error, and 64 people found responsible for the accidents were punished.

Jiang Jiemin, chairman of the State-owned Assets Supervision and Administration Commission of the State Council, and president of the CNPC at that time, was also given a disciplinary warning.

The most recent fire before Sunday's was on Nov 22, 2011, when lightning set two oil tanks ablaze at the Xingang Port in the city's Jinzhou New Area.