Washington, D.C.  (WOWO) — More than 8,000 flights were delayed across the United States on Sunday as air traffic controller absences continued to disrupt travel during the ongoing federal government shutdown, now in its 26th day.

U.S. Transportation Secretary Sean Duffy reported that the Federal Aviation Administration experienced staffing shortages at 22 air traffic control locations on Saturday. He added that additional shortages are expected in the coming days, which could lead to more flight delays and cancellations nationwide.

Airlines and travelers have been forced to adjust schedules as the shutdown continues to affect operations at multiple airports, heightening concerns for holiday travel and other peak periods.