Security alert at Washington Airport

State police explosives experts were investigating a suspicious item that forced gate evacuations at Dulles International Airport outside Washington on the eve of 9/11 anniversary events, a spokesman said.When a suspicious item was detected around 4:30 pm (2030 GMT), an area around a cargo container on an airfield was evacuated, said Robert Yingling, a Dulles airport spokesman.The evacuation areas perimeter included a few gates at concourse B of the facility, the largest international airport near the US capital, the spokesman said.The investigation of the suspicious item by the Virginia state police Explosive Ordinance Disposal unit was ongoing at 0015 GMT Sunday, Yingling added.Flights from the gates affected by the security alert were moved, and the airport remained open and operating with the investigation ongoing, the spokesman said.