Japan Now Also Investigating Boeing's Dreamliner Jet

Two fuel leaks in jets owned by Japan Airlines

Japan's transport ministry has launched an investigation into what caused two fuel leaks on a Boeing Co. 787 Dreamliner jet owned by Japan Airlines Co. , just days after U.S. authorities began a wide-ranging review of the aircraft in the wake of a series of incidents, including a battery fire.

Over the weekend, the JAL-operated jet, which was undergoing checks in Japan following a fuel leak at Boston airport in the United States last week, again leaked fuel during tests. Both leaks were due to separate valve-related problems.