A University of Virginia student honored as an “intellectual risk-taker” has been arrested in North Korea, its state-run media said Friday, accusing the American of an unspecified “hostile act” against the state. Otto Frederick Warmbier, 21, was detained Jan. 2 at Pyongyang airport as he prepared to leave after a five-day trip over the New Year’s holiday, said Gareth Johnson of Young Pioneer Tours, the agency that organized the trip. But Warmbier’s detention was not made public until Friday, when the official Korean Central News Agency said it was questioning him about taking part in “anti-state activity.” The brief statement gave no further information about the accusations or the current status of the student.