Malaysia Airlines officials confirmed Friday that the missing plane was carrying flammable lithium-ion batteries, prompting new speculation that the missing jetliner may have caught fire during its flight.

It’s been two weeks since the Beijing-bound flight vanished without a trace, but the latest revelation has led some to suggest that the batteries aboard the Boeing 777 may have started a fire on the plane which in turn caused it to crash.

Lithium-ion batteries, which are often used in electronic devices such as cameras and cellphones, have been known to cause fires when they overheat, including aboard planes.

According to the U.S. Federal Aviation Administration, more than 140 incidents involving batteries carried as cargo or baggage have been recorded between March 1991 and February 2014.

According to several reports, Malaysian Airlines CEO Ahmad Jauhari Yahya said Friday that Flight MH370 was carrying some “lithium-ion small batteries” but he insisted the battery cargo was checked several times to ensure it was packed according to guidelines.

There have also been incidents with battery systems built into the jetliners. The 787 jetliner, which was launched in 2011, is the first airliner to make extensive use of lithium-ion batteries.

In January 2013, a lithium-ion battery caught fire on an empty 787 plane parked at Logan International Airport in Boston, sparking a blaze that took firefighters 40 minutes to extinguish. Less than two weeks later, a battery aboard another 787 failed.

The fire at Logan airport forced a redesign of the lithium-ion battery system on the 787 jetliners, and prompted the FAA to request a review of the design, manufacture and assembly of the 787 model. It ultimately found that the 787 design is safe.

While Transport Canada says most lithium batteries are safe, the federal agency lists them as a dangerous good and says on its website that the batteries are a “cause for concern.”

“When shipping lithium batteries it is not always clear which mode of transport will be used. Your shipment may end up on an aircraft, and an aircraft’s fire suppression system may be unable to extinguish all types of lithium battery fire,” Transport Canada says.

In Canada, packages containing the batteries are subject to certain shipping requirements.

According to Transport Canada, computer batteries have heated up and caused fires on cargo and passenger planes. A charging lithium ion battery once exploded on a mini-submarine designed to carry U.S. Navy SEALS to shore.

Flight MH370, carrying 239 people, went missing shortly after taking off from Kuala Lumpur on March 7.

With files from The Associated Press