A man was escorted off a US flight after he got into a fight with another passenger over wearing a face mask, police have said.
Rylie Lansford, who was sat near both passengers on the Allegiant Air flight from Mesa, Arizona, said the fight broke out when a man sitting behind her started arguing with a flight attendant who asked him to wear a mask.
The man was wearing a face shield, but according to the airline's policy, face masks must also be worn.
Another passenger turned around and yelled at the man to wear a mask and began shouting obscenities and making threats, Ms Lansford said.
Police said the first man told him to "mind his own business".
As soon as the two men started fighting on the Utah-bound flight, Ms Lansford said she ran to the front of the plane and started recording the video.
The footage shows the man in front choking the passenger who refused to wear a mask, pulling his hair and hitting him in the back.
An off-duty police officer escorted the man who wouldn’t wear a mask off the flight, police said.
The second man was allowed to stay on the plane, Ms Lansford said.
"I was just annoyed that it was just one simple thing that one person had to do,” she said. “If you buy a plane ticket, wear a mask."
Allegiant Air confirmed the incident in an statement and said police were investigating.
The statement said: "While the passenger was being escorted off the plane, he had an altercation with another passenger. Law enforcement was called to assist."