With the gradual resumption of air travel in the United States, passengers refuse to comply with epidemic prevention regulations and clash with flight attendants frequently. There have been 3082 reports of passenger irregularities so far this year, of which 2350 (76 per cent) are related to masks, according to data released by the Federal Aviation Administration ((FAA)) on Tuesday.

As of June 20, FAA had launched 487 enforcement actions, far surpassing the previous record of 305 for the whole of 2004, the agency said.

So far this year, the agency has fined at least 60 people a total of $563800, including beating flight attendants and refusing to wear protective masks several times.

That includes a $124500 fine announced on Tuesday for eight people, including a man on a Southwest Airlines flight who hit a flight attendant on the chin for refusing to wear a mask, and a passenger on an Alaska Airlines flight who pushed a flight attendant, both in February.

"FAA will strictly implement the zero tolerance policy for passengers who disrupt flight order, violate FAA regulations, disobey crew instructions, or engage in acts prohibited by federal law," FAA said in a statement.

Despite the authorities' efforts to crack down on misconduct on board, there are still videos on social media of passengers beating flight attendants and volunteers suppressing unruly violators at the request of flight attendants.

The Federal Aviation Administration does not have the power to file criminal charges. Some aviation industry groups and trade unions sent a letter to the U.S. Department of Justice on Monday demanding criminal charges against unruly passengers.