Tokyo - Japan's two biggest airlines on Wednesday grounded all their Dreamliners in the most serious blow yet to Boeing's troubled next-generation model after an ANA flight was forced into an emergency landing.
The 787 Dreamliner has suffered more than a week of bad news that has prompted safety investigations by three national aviation regulators, although Boeing insists the plane is safe.
All Nippon Airways - the world's first carrier to receive the Dreamliner from Boeing after years of delays - said a battery problem triggered a cockpit error message that forced the pilots to land the plane in southwestern Japan.
ANA said instruments on the Dreamliner had detected smoke in a forward electrical compartment, and Japanese Transport Minister Akihiro Ota said it was a "serious incident that could have led to a serious accident".
Both Ota's ministry and the US Federal Aviation Administration broadened existing probes into the Dreamliner to encompass the ANA incident. Authorities in India said on Wednesday they were starting their own investigation.
Both ANA and its rival Japan Airlines (JAL) - which are among Boeing's biggest customers for the Dreamliner - said they would ground their entire 787 fleets pending safety checks.
ANA has 17 Dreamliners in operation and JAL has seven, and both have dozens more on order in deals worth billions of dollars for Boeing. Australia's Qantas said it was sticking by an order for 15 Dreamliners for its Jetstar affiliate.
ANA said 129 passengers and eight crew were on board the flight, which was headed from Ube in the far west to Tokyo when it diverted mid-flight to an airport in Takamatsu, on Japan's fourth largest island of Shikoku.
Injuries during evacuation
Police reported several "slight injuries" such as scratches after those aboard evacuated the plane via emergency chutes at Takamatsu, as fire trucks deployed on the ground.
One passenger was quoted by broadcaster NHK as saying he "smelled something strange" after take-off and feared the plane was going to crash.
Last week, there was a battery fire and smoke on an empty Dreamliner flight operated by JAL on the ground in the US city of Boston.
JAL said the smoke on that flight was traced to a fire from the battery used for the Dreamliner's auxiliary power unit, located at the rear of the plane.
Wednesday's incident involved the forward battery for the main power unit, ANA said.
"It is true that the aircraft has recently seen a series of troubles," ANA spokesperson Naoko Yamamoto said after the emergency landing. "But we cannot say if this has something in common with previous problems."
Boeing said after the Takamatsu incident: "We will be working with our customers and the appropriate regulatory agencies."
The high-profile incidents over the past week are the latest issues to dog the aircraft, after production glitches delayed delivery of the first plane to ANA by three years to 2011.
The problems bloomed last week with the small fire on the JAL flight after it had landed in Boston from Tokyo. That incident was followed by a fuel leak on another JAL Dreamliner, also in Boston.
A cracked cockpit window then forced the cancellation of a Dreamliner flight in Japan before a JAL-operated plane suffered a fuel spill on Sunday at Tokyo's Narita Airport.
On Friday the FAA in the United States announced an in-depth safety review of the 787's "design, manufacture and assembly". But Boeing insists that it has "complete confidence" in the plane.
Considered a milestone in the aviation industry with its use of lightweight composite materials and electronics instead of aluminium and hydraulics, some 50 of the US aerospace giant's 787s are in service worldwide.
Boeing, which outsourced much of the production to Japanese and other contractors, says the plane's impressive fuel efficiency represents a revolution in aircraft design.
But questions about its safety, and the US and Japanese government reviews, have the potential to affect sales. Boeing has more than 800 Dreamliners on order.