WASHINGTON — Southwest Airlines grounded plans that were set for departures Wednesday afternoon while the low-cost carrier investigated problems with its computer system, the airline said.

As a result, delays were stacking up at airports used by Southwest across the country.

The carrier posted on Twitter that its flight status and check-in were working. Passengers are encouraged to check the status of their flight.

Reagan National Airport was telling passengers to give themselves extra time to check in if they are set to fly out on a Southwest flight.

Southwest posted on Twitter that it was investigating the problems with its computer systems, telling frustrated passengers that it is a “tech outage.”

Stay with WTOP for updates on this developing story.