Transport minister Akihiro Ota said Tuesday he has ordered Japan Airlines Co. and All Nippon Airways Co. to inspect all of their Boeing 787 Dreamliners after one operated by JAL experienced a problem with its battery container Sunday.

Ota also urged the carriers to review their methodology for overseeing maintenance work by Boeing Co., which had modified the aircraft's battery system.

"It is regrettable that (the aircraft's maintenance) was not perfect," Ota told a news conference over the incident, which occurred just one day after the airlines resumed regular services using 787s. The planes had been grounded for more than four months because of battery problems.

On Sunday, a sensor showed a difference in air pressure inside and outside the stainless steel battery container aboard the JAL plane, which was scheduled to fly from Tokyo to Beijing.

According to JAL, the difference in air pressure was believed due to faulty maintenance by Boeing, because two small holes in the container were mistakenly sealed when the plane-maker repaired the battery system.

In a similar incident, a power switchboard was partially damaged by heat during a 787 training flight conducted by ANA on May 4 due to faulty maintenance by Boeing.

Ota said the incidents had no adverse effect on the safety of flight operations, "but appropriate measures should be taken as it made passengers anxious."