A piece of baggage exploded after it was run over by a luggage vehicle at Midway Airport in Chicago on Monday, prompting a bomb squad to respond.

The incident occurred at about 12:20 p.m. local time when a bag fell off the transport and made a popping sound, according to NBC Chicago. A bomb squad was called to Midway to evaluate the suitcase and determined there was no threat to public safety.

The explosion was caused by either a cellphone battery or charger, according to Chicago Police Department spokesman Anthony Guglielmi, who tweeted that "the bag was actually run over by a luggage vehicle and did not combust or explode on its own."

No one was injured and the airport has resumed normal operations.