Federal authorities in the District and Ohio are investigating a bomb threat made from an airport ticket counter Sunday that closed Reagan National Airport for a portion of the afternoon.

The threat placed the bomb on U.S. Airways flight 2596 from Dayton, Ohio to Washington, D.C.'s National Airport. After the plane landed Sunday afternoon, authorities swept the aircraft, and interviewed all 44 passengers aboard. No explosives were found and the plane was declared safe four hours later.

The incident temporarily halted flights at Reagan National Airport yesterday.

Authorities say a person, who was not identified, made the bomb threat at a ticket counter in Dayton. Airport police took that person to a mental health facility without immediately filing charges.

A spokesperson for the district office of the FBI says they have no reason to believe anyone else was involved in the incident.

Although the threat was received while the plane was in the air, an airport spokesperson says the aircraft was close enough to Reagan National to allow it to proceed.

The threat shut down the airport for approximately 20 minutes.