Updated May 28, 2021 at 9:41 PM ET

A flight attendant on a Southwest Airlines plane lost two teeth over the weekend after allegedly being punched by a passenger who had "repeatedly ignored standard inflight instructions," according to an airline spokesman.

The Port of San Diego Harbor Police Department charged Vyvianna Quinonez, 28, with battery causing serious bodily injury in the incident, which was caught on video and later went viral.

The incident sparked widespread outrage, but for flight attendants it was just the latest example of an increase in travelers becoming disorderly and in some cases turning violent against those tasked with enforcing federal and airline rules.

Southwest Airlines said Friday it would delay its return to serving alcohol to passengers "given the recent uptick in industry-wide incidents of passenger disruptions inflight."

"We realize this decision may be disappointing for some Customers, but we feel this is the right decision at this time in the interest of the Safety and comfort of all Customers and Crew onboard," the airline said in an email.

The FAA is keeping track of attacks

The number of unruly passengers on U.S flights has taken off in 2021, with many more people boarding planes as the pandemic eases.

According to the Federal Aviation Administration, from Jan. 1 through May 24, there were roughly 2,500 reports of unruly behavior by passengers, including about 1,900 reports of people contravening the federal mask mandate, which is still in place.

The FAA has not always tracked unruly passenger reports but began keeping a tally last year as it started to observe a surge in complaints, specifically around noncompliance with the face-covering mandate, said FAA spokesperson Ian Gregor.

"Based on our experience, we can say with confidence that the number of reports we've received during the past several months are significantly higher than the numbers we've seen in the past," Gregor said in an email.

The FAA does, however, keep data on the number of "unruly passenger" violations it has identified. Through May 25, the agency has already recorded 394 potential violations, while in all of 2019 and 2020 there were just 146 and 183 violations, respectively.

Flight attendant unions say the hostility is unprecedented

Sara Nelson, president of the Association of Flight Attendants-CWA, which represents nearly 50,000 flight attendants across 17 airlines, said the level of hostility toward flight attendants is unprecedented.

"We've never before seen aggression and violence on our planes like we have in the past five months," Nelson said in a statement. "The constant combative attitude over wearing masks is exhausting and sometimes horrific for the people who have been on the front lines of this pandemic for over a year."

Nelson said the strained situation is causing some flight attendants to quit.

The surge in unruly passenger complaints is also getting the attention of federal officials, who have warned travelers to be on their best behavior in airports and on planes or risk facing the consequences.

"Let me be clear in underscoring something," Homeland Security Secretary Alejandro Mayorkas said during a Tuesday press conference. "It is a federal mandate that one must wear a mask in an airport, in the modes of public transportation, on the airplane itself — and we will not tolerate behavior that violates the law."

Just this week the FAA announced that it was proposing civil penalties as high as $15,000 against five more passengers for violations that included allegedly assaulting and yelling at flight attendants.

In an open letter, Lyn Montgomery, president of TWU Local 556, the union for Southwest flight attendants, suggested the airline be more consistent in banning unruly passengers and called for an increase in the number of federal air marshals on planes.

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