A fellow passenger on the flight from Nashville to Charlotte, Joe Timmons, tells ABC News that the "passenger refused to wear a mask and became verbally abusive in flight."
The Charlotte Police Department said officers only assisted in resolving the incident and "no passengers were arrested or charged."
In a statement, Southwest wrote: "Our reports indicate that two customers were engaged in a verbal altercation onboard Flight #730 from Nashville to Charlotte on Thursday. As a result, local law enforcement officers were asked to meet the flight upon arrival."
The recent incident is only the latest in a series of aggressions on airplanes.
The Federal Aviation Administration (FAA) said that airlines have reported 3,000 cases of disruptive passengers this year, and the vast majority -- 2,300 -- involve people who refused to wear a mask. The highest number of potential violations of federal law since they began keeping records in 1995.