The world’s busiest airline has cited a combination of heavy winds at two major hubs and staffing shortages for the travel chaos.

American Airlines has confirmed to Newsweek some 338 flights were canceled today, representing 6 percent of its total schedule.

This is compared to 1,060 flights grounded on Sunday, 548 on Saturday and 343 on Friday—meaning 2,289 flights have been disrupted in the past four days.

David Seymour, the airline’s chief operating officer, said in a note to employees seen by CNN: “With additional weather throughout the system, our staffing begins to run tight as crew members end up out of their regular flight sequences.

“To make sure we are taking care of our customers and providing scheduling certainty for our crews, we have adjusted our operation for the last few days this month by proactively canceling some flights.”

The ongoing travel chaos saw several would-be American Airlines passengers take to social media and express their frustration.

Posting an accompanying screen appearing to indicate her flights had been postponed for a second consecutive day, Twitter user J Nikol Jackson-Beckham said: “Absolutely NOT what I wanted to wake up to on Monday.

She had added in a previous tweet today: “Please @AmericanAir … I just want to go home. “Getting home a day late after missing a family wedding and eating the cost of a hotel as going to suck already. But being stranded ANOTHER day is unacceptable.”

Twitter user Kimber Lee wrote on Monday: “Thanks @AmericanAir for just cancelling my flight as I’m on the way to the airport. And making it impossible to rebook. Ughhhhhh.”

Will Tyler tweeted his dissatisfaction about American Airlines on Sunday, writing: “Still don’t have my luggage after canceling our flight. Can’t get customer service on the phone. DM hasn’t been responded to in 12 hours. Absolutely the worst travel experience of my life.”

The official American Airlines Twitter account took the opportunity to inform people affected by the continuing disruption they are entitled to their money back, writing: “Our Refund policy is the same no matter what the cause of the delay is. If you’re no longer traveling we can refund the unflown flight.”

Aviation website FlightAware showed American Airlines flights scheduled to leave major airports LAX and Denver and on Monday morning.

American Airlines has announced a plan to boost employee numbers, with approximately 1,800 flight attendants returning from leave and over 600 new flight attendants starting by the end of 2021.

Southwest has also announced it is recruiting staff, intending to have up to 5,000 new employees by the end of this year.

Skywest Airlines customers faced flight delays and cancellations across the U.S. two weeks ago, following a computer glitch.