Raed Saleh, a Syrian national, landed at Dulles International Airport outside Washington on Monday afternoon after an 11-hour journey from Turkey. In his passport was a visa for the U.S.

He was planning to attend a Tuesday evening banquet in the capital where he was being honored for his rescue work in Syria. But as Saleh tried to make his way through immigration, he says, he was pulled aside by security at the airport.

“After about two or three hours, they told me, ‘We apologize but you must return to Turkey because this visa has been canceled. It’s not valid.’ I told them, ‘How isn’t it valid? It’s good for six months.’ ”

Saleh says the immigration official could not tell him why he was being turned back.

“He told me, ‘I don’t have any explanation or details. I can’t tell you anything,’ ” according to Saleh, who spoke to NPR via Skype. He was in Geneva, on his way back to Turkey.

Saleh had to head back without the award he was to receive from InterAction, an alliance of international humanitarian and aid agencies.

Saleh heads up Syria Civil Defense, also known as the White Helmets, a collection of 2,800 volunteer rescue workers who help victims caught up in the war.

“Their group really responds when buildings have been damaged from bombings or other kind of strikes and they go in and they pull people out of the rubble,” says Nancy Wilson, the head of Relief International, which nominated Saleh for the award.

Read the full article on NPR.org.