Dec 2, 2011 -- JFE Holdings Inc., Japan’s second- largest steelmaker, said its steel mill in Chiba, near Tokyo, is operating normally after four workers were injured by an explosion at JFE Chemical Co.’s sulfuric acid tank.

The explosion, which occurred within the site of JFE’s steel works at 9:55 a.m., Japan time, didn’t cause a fire and hasn’t impacted steel production, spokesman Seiji Iwashita said today by telephone.

JFE is investigating the cause of the accident, he said. JFE Chemical is a wholly owned unit of JFE.