Departures at the US capital's Reagan National Airport were halted for an hour and a half on Monday due to a shooting at the US Navy Yard.
The Federal Aviation Administration lifted a ground stop mid-morning that had been imposed due to the nearby incident, airport spokesman Chris Paolino said.
"Flights have begun to depart, but we expect residual delays as the airport returns to normal operations," Paolino told AFP via email.
"The ground stop was in place for approximately 90 min," he added.
Earlier, Paolino said departures had been halted due to shooting but that inbound aircraft were still landing and that the airport remained open.
Several people have been wounded in the shooting at the nearby US Navy Yard, authorities said.
The Navy said at least three shots were fired at 8.20am (1320 GMT) in the headquarters building of the Naval Sea Systems Command.
About 3,000 people work at the headquarters, which is responsible for building and buying US warships and combat systems, the Navy said.
The complex also has a residence that serves as the home of the chief of the US Navy.