American Airlines has suspended one of its employees after a video posted online showed him threatening a passenger on board a flight. 

Witnesses say the incident started after a woman was told she couldn't bring her stroller onto the plane. 

When another passenger rose to her defense, the employee reportedly challenged him to a fight. 

In a statement, American Airlines apologized to the customer and other passengers affected by the incident. It comes two weeks after a 69-year-old doctor was hospitalized after United Airlines ordered police to forcefully remove him from his seat to make room for airline staff.