SAN FRANCISCO/NEW YORK - American Airlines has suspended an employee caught on a video clip in a confrontation with a female passenger.

The airline said in a statement it was investigating the confrontation that began shortly after noon on Friday when the woman's baby stroller was removed from a jetliner during boarding at San Francisco International Airport .

Posted on the same day on Facebook by fellow passenger Surain Adyanthaya, the video shows a female passenger crying at the front of the plane as she is holding her baby.

Adyanthaya said in the caption that a flight attendant "violently took a stroller from a lady with her baby ... hitting her and just missing the baby".

A male passenger is seen in the clip getting up and demanding the name of the flight attendant who removed the stroller.

The male passenger stands up and yells at the flight attendant: "You do that to me and I'll knock you flat."

"You stay out of this!" the attendant responds, pointing at the male passenger and challenging the passenger to hit him. The video shows the man eventually returning to his seat.

American Airlines said in a statement it was investigating the incident, which took place before the plane took off on a flight from San Francisco to Dallas.

"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 airline said in a statement released early on Saturday.

The woman elected to take another flight and was upgraded to first class, said American.

The treatment of passengers by the airline industry returned as a national issue after a video appeared online two weeks ago showing a 69-year-old passenger being dragged off a United Airlines flight to make room for a crew member. The fracas sparked international outrage and policy changes by the airline.

A passenger who posted a description of the latest incident on the website Reddit wrote that the flight attendant early on called for security to intervene in his dispute with the woman.

Bob Ross, president of the Association of Professional Flight Attendants union, which represents American Airlines workers, said in a statement that tight schedules, overcrowded planes, shrinking seats and limited overhead bin space have made it difficult for flight attendants to board passengers.

"All of these factors are related to corporate decisions beyond the control of passengers and flight attendants," Ross said.