Authorities cleared a suspicious van after evacuating part of the main terminal of Dulles International Airport as part of a security perimeter Thursday, according to an airport spokesman.
The perimeter was set up as a precaution after a K-9 hit on the white van parked on the departure roadway between doors four and five.
Police used a robot to investigate and clear the van.
People are allowed back into the closed portion of the terminal, and cars are allowed back on the upper road.
Virginia State Police assisted.
Flights continued operating throughout the incident, which began about 5 p.m.
