CHANTILLY, Va. (AP) — Officials say an investigation into a bomb threat at Washington Dulles International Airport delayed several arriving flights, but no bomb was found.

Metropolitan Washington Airports Authority spokeswoman Kimberly Gibbs said early Tuesday that authorities conducted an investigation at the airport Monday night. Gibbs says the investigation involved two parking garages and that they were closed to the public until about 10 p.m.

No further details about the investigation or bomb threat have been released.

Gibbs said delays affected flights scheduled to arrive between 8:30 p.m. and 9 p.m.

No injuries or arrests have been reported. Flights were back to normal.