Airways canceled lots of extra flights Sunday, citing staffing issues tied to COVID-19, because the nation’s journey woes prolonged past Christmas, with no clear indication when regular schedules would resume.

Greater than 700 flights getting into, leaving or flying throughout the U.S. had been known as off, in line with the flight-tracking web site FlightAware. That determine was down from almost 1,000 on Saturday. Greater than 50 flights had been already canceled for Monday.