American Airlines flight attendant put on leave after clash with passengers captured on video The airlines said it is investigating the incident.

 -- It's been less than two weeks since a video of a bloodied passenger being dragged off a United Airlines aircraft ignited a national discussion about the airline industry’s treatment of passengers, and now, yet another onboard incident captured on video is raising eyebrows -- and it's resulted in the immediate grounding of a flight attendant.

A video posted to Facebook on Friday by Surain Adyanthaya -- a passenger onboard American Airlines flight 591, from San Francisco to Dallas -- shows an intense confrontation between a flight attendant and at least two passengers at the front of the aircraft while it is still on the tarmac in San Francisco.

The heated moment began when a flight attendant took away a stroller from a female passenger, Adyanthaya told ABC affiliate WFAA in Dallas, which reported that the woman was from Argentina and traveling with her two children.

The nearly three-minute video starts with the woman crying and asking the flight attendant to give her back the stroller.

The incident appears to escalate when a male passenger comes to the woman's defense, saying to the flight attendant, "Hey bud, hey bud, you do that to me and I'll knock you flat!"

The flight attendant, who is visibly angry, points his finger at the passenger and says, "Hey, you stay out of this!"

A pilot appears to attempt to calm down the flight attendant.

During the entire video, the female passenger continues to be heard crying.

American Airlines responded publicly to the incident shortly after the video began to circulate online, announcing in a statement that the flight attendant had been put on leave while the incident was investigated and that the woman and her family were upgraded to first-class for the remainder of their international trip.

An American Airlines spokesperson told ABC News that the woman passenger brought a double-wide stroller onto a single-aisle plane.

The airlines’ rules for passengers traveling with children say strollers should be checked at the gate.

The airline spokesperson told ABC News that when the passenger tried to jam the stroller down the plane aisle, a flight attendant tried to tell her she needed to gate-check it. The woman began to cry, after which another passenger got involved, and the situation escalated from there, according to the airline spokesperson.

The spokesperson said the flight attendant should not have become confrontational with any passenger.

American Airlines in its statement said, "What we see on this video does not reflect our values or how we care for our customers. We are deeply sorry for the pain we have caused this passenger and her family and to any other customers affected by the incident."

The statement continued, "The actions of our team member captured here do not appear to reflect patience or empathy, two values necessary for customer care. In short, we are disappointed by these actions. The American team member has been removed from duty while we immediately investigate this incident."

ABC News' Morgan Winsor contributed to this report.