WASHINGTON — Operations resumed at Reagan Washington National Airport on Tuesday after a brief halt because of a bomb threat against a United Airlines plane.

The FBI said it had responded to the report and found nothing hazardous.

The U.S. Federal Aviation Administration said operations resumed around 1 p.m. ET after a ground stop at the airport that lasted for about an hour.

United said Flight 512 — a Boeing 737 MAX 8 with 95 passengers and crew that had departed Houston — had landed without incident.

After passengers deplaned, the aircraft was moved away from the terminal while authorities investigated.

More than 300 flights, or 37% of traffic, were delayed at Reagan Airport, according to FlightAware, a flight tracking site. There have been significant flight delays in the U.S. over the last month due to a government shutdown and air traffic control absences.

Reagan Airport is just five miles from the White House and U.S. Capitol and the FAA imposes special security restrictions around the airspace.