At least four people from an American Airlines flight out of Boston, including three crew members and one passenger, were removed from a flight and taken to a local hospital, officials tell WCVB-TV.

Passengers aboard Flight 1719 from Boston, Massachusetts, to Charlotte, North Carolina, reported an odor in the cabin New Year’s Day and the plane was forced to return to the airport gate. The airline told local news outlets that the plane was carrying 120 passengers and 5 crew members.

In addition to confirming the presence of an odor in the cabin, Massport confirmed that the four people were taken to local hospitals for evaluation.

American Airlines representatives told local news outlets that a “mechanical issue” was to blame for the incident and that the jet was now being taken out of service. The remaining passengers on the plane are being rerouted and American Airlines’ website lists the initial 1:05 p.m. departure time as delayed 3 hours and 40 minutes as of publish time.