A telephone threat led to the evacuation of a U.S. international airport in the state of Virginia, causing flight delays and hundreds of stranded travelers, airport officials said Tuesday. Richmond International Airport spokesman Troy Bell told the Richmond Times-Dispatch newspaper that the facility received a telephone call of a threatening nature early Tuesday morning, causing officials to clear the terminal. Virginia State Police Sargent Thomas Molnar said the threat was determined to be credible. Federal, state, and local law enforcement officers responded by assisting in searching the airport terminal and searching the parking garages. Airport spokesman Bell said the terminal was reopened to airline workers about three hours later Tuesday morning. Public access would soon follow, Bell told the newspaper. At least 12 flight departures were delayed and a smaller number of arrivals were also delayed, the Richmond Times-Dispatch newspaper reported.