The Federal Aviation Administration announced Wednesday that two passengers could face tens of thousands of dollars in fines for refusing orders from flight attendants to wear masks and, in one case, shouting obscenities.

A woman on a Dec. 27 JetBlue flight from Boston to Puerto Rico refused multiple requests to wear her mask and remain seated with her seat belt fastened, authorities said. The woman allegedly shoved a flight attendant multiple times, shouted obscenities at her and then threatened to have her fired.

As a result of the woman’s behavior, the captain diverted the flight back to Boston. The woman faces a potential fine of $20,000, the FAA said.

Less than a week later, another JetBlue passenger on a Dec. 31 flight from New York to the Dominican Republic allegedly refused flight attendants’ instructions to wear his mask and to stop drinking from a bottle of alcohol he’d brought on board and turn it over to crew members. When flight attendants gave the man a “Notice to Cease Objectionable Behavior” card, he shouted profanities at them, slammed overhead bins and became more uncooperative, authorities said.

As the plane was preparing to land and taxiing to the gate with the “Fasten seat belt” sign illuminated, the man allegedly threw his bottle of alcohol behind a seat and went to the lavatory. He was met at the gate by law enforcement officers. The FAA is proposing a $12,250 fine.

The FAA does not identify individuals against whom it proposes civil penalties.

The two cases come the same week the agency announced it will extend a “zero-tolerance” policy for bad behavior put into place in January as part of a stepped-up effort to ensure that people are complying with federal mask mandates for transportation. The order had been set to expire at the end of March, but FAA Administrator Steve Dickson said this week the agency would extend it.

Airlines have reported more than 500 unruly passenger cases to the agency since December. The FAA is reviewing roughly 450 incidents of unruly behavior by passengers and has opened 20 formal enforcement cases.

Dickson said the majority of the cases involve refusal to wear masks but also include other incidents. He said the special order will be extended as long as the federal mask order remains in place.

Last week, the FAA announced it was seeking a fine of $14,500 against a man accused of refusing to wear a mask on another JetBlue flight from New York to Dominican Republican on Dec. 23. In that instance, the pilot returned to New York after the man allegedly ignored warnings from flight attendants that he had to wear a face covering.

Individuals have 30 days once they’ve received the FAA’s enforcement letter to respond.

The Centers for Disease Control and Prevention issued a sweeping mandate requiring masks on planes and other forms of transportation in January. The Transportation Security Administration, which also has the authority to enforce the mask mandate, said violating those rules could come with fines of more than $1,000.