TOKYO: At least thirteen people were injured Wednesday after an explosion at a steel plant in central Japan, an official said, the latest in a series of accidents at the site.
Television pictures showed clouds of black smoke billowing from the Nippon Steel and Sumitomo Metal facility in Tokai, where 3,000 employees were engaged in producing steel sheets and pipes.
A spokesman for the Aichi prefectural police said the fire department had been alerted to a problem at the plant at 12:46 pm (0346 GMT).
A Tokyo-based spokeswoman for the world's number-two steelmaker said 13 people were injured, "nine of them employees (of Nippon Steel) ...and four of them employees of its partner companies."
At least six people were taken to hospital, private broadcaster Nippon TV reported, saying the injuries were not life-threatening.
Another local report said 15 people were injured, three of them severely.
"There was a small explosion that was caused by a fire at a coke oven," a Tokai city official told AFP, adding he did not know about the severity of the injuries.
The explosion came after other fire troubles earlier this year. No one was hurt in separate incidents in January, June and July at the same plant
The incidents prompted the mayor of Tokai, a city of about 100,000 people, formally to ask the steelmaker to draw up a plan to deal with any safety problems.
Mayor Atsuo Suzuki submitted the request twice in the wake of separate incidents, according to local media.
Four incidents this year were related to power blackouts, the company spokeswoman said, adding that Wednesday's problem was caused by another issue.
"The fire broke out during the process right before coal is thrown into a coke oven," she said.
Unlike in neighbouring China, industrial accidents are relatively rare in Japan where safety measures are usually strictly enforced.
Last month the plant announced preventive measures, including setting up a committee to investigate details of past incidents and overhauling the site's power supply systems.
The plant manufactures a wide range of steel products, from high-quality steel sheets for vehicle bodies to products for canned food as well as various kinds of steel pipes.
Nippon Steel's Tokyo-listed shares closed down 1.6 percent to 274.9 yen as the broader market added 0.38 percent.