CNN  — 

The Federal Aviation Administration will extend its stricter enforcement against unruly passengers – specifically targeting those who disobey masking policies – after receiving more than 500 reports of misbehaving passengers since December, the agency said Monday.

“The number of cases we’re seeing is still far too high, and it tells us urgent action continues to be required,” FAA Administrator Steve Dickson said.

The announcement was made as the Transportation Security Administration (TSA) said that more people have traveled by air in the last four days than during any other similar-length period during the pandemic.

The TSA said it screened 1,344,128 people at airports on Sunday, meaning 5.2 million had flown since Thursday. On Friday, 1,357,111 passengers were screened, the highest single-day number since March 15, 2020.

While the increase in travel is good news for the struggling airline industry, the uptick in passengers could mean an increase in in-flight incidents.

The FAA’s Dickson said he has instructed agency officials to consider both civil fines and criminal charges for reports of unruly passengers.

“I have decided to extend the FAA’s unruly-passenger zero-tolerance policy as we continue to do everything we can to confront the pandemic,” he said in a statement. “The policy directs our safety inspectors and attorneys to take strong enforcement action against any passenger who disrupts or threatens the safety of a flight, with penalties ranging from fines to jail time.”

The stepped-up enforcement had been set to expire at the end of the month but will now remain in place until the Centers for Disease Control and Prevention lifts its order requiring face masks be worn on mass and commercial transit modes.

FAA reviewing more than 450 unruly passenger reports

The reporting period for the more than 500 complaints of unruly passengers included the time around the Capitol riot. Previously, CNN had reported several attendees struggled to gain access to flights following the riot, with some being put on no-fly lists.

The FAA is currently reviewing more than 450 cases and have begun taking action against unruly passengers in 20 cases, it said.

At least four fines have been imposed on passengers under the stricter enforcement policy, the largest being for $27,500.

The agency said individuals who are fined may respond to the agency, and it has not publicized the final amount those individuals paid.

The passengers who have thus far been fined are accused of, in addition to not wearing masks, assaulting flight attendants, shouting obscenities, and drinking unapproved alcohol on planes.

In June, CNN reported that American Airlines had to temporarily suspend a passenger from its flights after the person refused to wear a face mask.

Other airlines permanently banned passengers for not following guidelines, including Delta, which banned 460 anti-maskers.

While the FAA has not revealed how many cases it is pursuing against passengers, the agency said about a month ago that across all modes of transportation, it had received reports of “fewer than 1,000 passengers … refusing to wear a face mask.”

The president of a major flight attendant union that had called for the policy to be extended called it an “important deterrent.”

“The patchwork, politically skewed discussion around masks has created confusion and conflict,” said Sara Nelson of the Association of Flight Attendants-CWA. “We don’t have time for failure to comply with the federal mask mandate. On an airplane, that behavior puts everyone at risk and we can’t stand for that.”

The FAA penalties are separate from those that the TSA may issue under a set of security directives.

CNN’s Pete Muntean contributed to this report.