Violent and unruly airline passengers will continue to face steep fines and potential criminal charges even as rules mandating face coverings fade away.

The U.S. Federal Aviation Administration on Wednesday said its zero-tolerance policy against unruly passengers will be made permanent as it attempts to deter bad behavior. The move came two days after most major U.S. airlines eliminated policies requiring passengers to wear masks, an issue that has contributed to thousands of attacks on airline personnel since the FAA began its crackdown in January 2021.

“Behaving dangerously on a plane will cost you; that’s a promise,” Acting FAA Administrator Billy Nolen said in an emailed statement. The agency can impose fines of as much as $37,000 per violation. The FAA had referred 80 cases for prosecution as of Feb. 16.

More than 1,200 unruly passenger incidents were reported this year through mid-April, roughly 800 of which were related to masks, according to the FAA. While the number of incidents is far above pre-pandemic years, the rate per flight has declined more than 60% from its peak, according to agency data. Airlines have been working with the Biden administration to create a nationwide no-fly list to ban the worst offenders.