The Transportation Security Administration (TSA) will resume self-defense classes for flight attendants and pilots after not having the training for more than a year due to the COVID-19 pandemic. The classes come as the airlines deal with a surge in cases of unruly passengers and violent behavior on flights.

With unruly passenger incidents on the rise, TSA remains committed to equip flight crews with another tool to keep crews safe, according to its statement. 

The Federal Aviation Administration has documented 3,082 reports of unruly passengers on flights this year, and a majority of those have been tied to mask disputes, according to the New York Times. The FAA has initiated investigations into 487 of the cases so far this year which allots to more than triple the number of investigations in the 12 months of 2019.