Tesla is under investigation for faulty electronic door handles that can trap people inside their vehicles.

The National Highway Traffic Safety Administration (NHTSA) launched the probe, saying it was responding to numerous complaints filed by Tesla owners, with a particular focus on children who have been locked inside the vehicle without any way to get out. The news comes a few days after Bloomberg published a bombshell report about Tesla owners who have been seriously injured after becoming trapped in their vehicles after crashes.

Tesla’s door handles, which operate electronically and sit flush against the vehicle for improved aerodynamics, have been the source of some consternation for some time. China’s government is considering banning electronic door handles for safety reasons. And now NHTSA says it is investigating instances in which Tesla’s handles become inoperable as a result of low-voltage battery problems.

The investigation specifically focuses on an estimated 174,290 Model Y SUVs, though the regulator said the investigation could widen:

This investigation will also assess the approach used by Tesla to supply power to the door locks and the reliability of the applicable power supplies. At this time, NHTSA’s investigation is focused on the operability of the electronic door locks from outside of the vehicle as that circumstance is the only one in which
there is no manual way to open the door. The agency will continue to monitor any reports of entrapment involving opening doors from inside of the vehicle, and [Office of Defects Investigation] will take further action as needed.

NHTSA says its investigation was prompted by nine instances of children becoming trapped inside a Tesla vehicle as a result of low-voltage battery problems. Typically, parents were unable to reopen their Tesla’s doors to retrieve their children from the backseat. Tesla’s vehicles contain manual door releases, but the agency notes that certain people, especially children, may not be able to operate them.

“Entrapment in a vehicle is particularly concerning in emergency situations, such as when children are entrapped in a hot vehicle,” the agency states.

This is the latest investigation to target Tesla. The company is also being examined for failing to report crashes involving its partially autonomous driving technology in a timely manner, and for its remote parking feature after several crash incidents were reported.