Federal Aviation Administration will make permanent its “zero tolerance” policy against disruptive passengers, according to the FAA .

Billy Nolen, acting administrator of the agency, stated in a statement that “Behaving unsafely on a flight will result in you being fined.”

The FAA’s decision to maintain stricter rules comes just days after major U.S. airlines stated they would not require passengers to wear masks. These rules angered some passengers and led many attacks on airline employees.

The FAA adopted the stricter rules in the wake of the attack on the U.S. Capitol on January 6. They can impose fines up to 37,000 on anyone who threatens or assaults others on commercial aircraft. The agency usually tries to discourage this behavior by issuing formal warnings, before resorting to financial sanctions.

For criminal prosecution, the FAA can refer people to Justice Department. It had already referred 80 cases to the Justice Department for investigation as of February 2, 2018. It is working with the Transportation Security Agency in order to revoke TSA PreCheck for passengers who are not following the rules.

According to the FAA, there were almost 6,000 reports about unruly behavior on flights by 2021. This includes assaults on crew members and other passengers. According to FAA figures, 800 of the 1,200 unruly passengers who were reported between April and May this year were related with masks.

These incidents are continuing, with a passenger being arrested Wednesday on disorderly conduct charges. He was accused of using a plane’s emergency slides, and exiting the aircraft at Buffalo, New York.