A group of six New York City teenagers stole an MTA bus in the Bronx Sunday and took it for a four-hour, three-borough joy ride before returning it to the same neighborhood, authorities said Sunday. The theft occurred less than a day after a different group of teens boarded a bus at an unattended MTA garage in Brooklyn, the New York Daily News reports. Authorities believe that the thefts may be linked. Officials have no idea how the Brooklyn teens started the bus’ engine—but when they did, they triggered the automatic security system, which captured video footage of the culprits. Authorities do not appear to have made any arrests yet in connection with either case.