Yet another investigation has launched to examine randomly exploding automotive airbags; however, this time, the problem seems to be isolated to Mazda CX-9 crossover SUVs.

The Detroit Free Press reports that safety regulators in the United States are currently observing reports of the car's side-impact curtain airbags activating without any apparent reason.

So far, two owners supposedly reported that their airbags went off suddenly while driving, according to information shared by the National Highway Traffic Safety Administration. A total of four people were injured in one specific case.

Both complaints featured similar instances where the driver and passenger side airbags deployed without any known cause while the car was driving.

The investigation so far only involves the first-generation CX-9, produced between 2010 and 2013. During that period, Mazda reportedly sold more than 112,000 examples of the crossover.

The NHTSA is currently looking into the matter and will determine the frequency of the problem and whether or not it will mandate that Mazda issue a recall for those models.

Although meant to save lives in the event of a collision, airbags have undergone significant scrutiny after the world’s largest supplier of the equipment, Takata, was forced to recall almost its entire stock of airbags for hundreds of vehicles over the past several decades due to faulty actuators. This eventually led to the once-billion-dollar-company filing bankruptcy.

The name of the CX-9's side-curtain airbag manufacturer is yet to be disclosed and, at this point, the investigation is being treated separately from the previously issued Takata recall.