Airlines continued to cancel hundreds of flights Saturday as staffing issues tied to COVID-19disrupted holiday celebrations during one of the busiest travel times of the year.

FlightAware, a flight-tracking website, noted 941 flights entering, leaving or inside the U.S. canceled Saturday, up from 690 Friday. Over 200 more flights were already canceled for Sunday. FlightAware does not say why flights are canceled.

Delta, United and JetBlue on Friday had all said the omicron variant was causing staffing problems leading to flight cancellations. United spokesperson Maddie King said staffing shortages were still causing cancellations and it was unclear when normal operations would return. “This was unexpected,” she said of omicron’s impact on staffing. Delta and JetBlue did not immediately respond to questions Saturday.

According to FlightAware, the three airlines canceled more than 10% of their Saturday scheduled flights. American Airlines also canceled 90 flights Saturday, about 3% of its schedule, according to FlightAware. American spokesperson Derek Walls said the cancellations stemmed from “COVID-related sick calls” and the airline contacted customers on Friday. European and Australian airlines have also canceled holiday-season flights due to staffing problems tied to COVID.

For travelers, that meant time away from loved ones, chaos at the airport and the stress of spending hours online and on the phone trying to rebook flights. Peter Bockman, a retired actor, and his daughter Malaika, a college student, were supposed to be in Senegal on Saturday celebrating with relatives they hadn’t seen in a decade. But their 7:30 p.m. flight Friday from New York to Dakar was canceled, which they only found out when they got to the airport. They were there until 2 a.m. trying to rebook a flight.

“Nobody was organizing, trying to sort things out,” he said, faulting Delta for a lack of customer service. “Nobody explained anything. Not even, ‘Oh we’re so sorry, this is what we can do to help you.’”

Their new flight, for Monday evening, has a layover in Paris, and they are worried there will be issues with that one as well. And they have already missed a big family get-together that was scheduled for Saturday.

FlightAware, which does not give a reason for why flights are canceled, said airlines scrapped nearly 6,000 flights globally on Friday, Saturday and Sunday as of Saturday afternoon, with almost one-third of affected flights to, from or within the United States. Chinese airlines made up many of the canceled flights, and Chinese airports topped FlightAware’s lists of those with most cancellations. China has strict pandemic control measures including frequent lockdowns, and the government set one on Xi’an, a city of 13 million people, earlier this week.

Air China, China Eastern and Lion Air, an Indonesian airline with many canceled flights, did not respond to emails Saturday.

Flight delays and cancellations tied to staffing shortages have been a regular problem for the U.S. airline industry this year. Airlines encouraged workers to quit in 2020, when air travel collapsed, and were caught short-staffed this year as travel recovered.

To ease staffing shortages, countries including Spain and the U.K. have reduced the length of COVID-19 quarantines by letting people return to work sooner after testing positive or being exposed to the virus.

Delta CEO Ed Bastian was among those who have called on the Biden administration to take similar steps or risk further disruptions in air travel. On Thursday, the U.S. shortened COVID-19 isolation rules for health care workers only.

(AP)