SEOUL — A graduate student accused of flying drones to North Korea was arrested Thursday following a court hearing on his warrant where he had apparently denied the main charges against him. A judge at the Seoul Central District Court approved the warrant, citing concerns that the suspect could flee or destroy evidence. The 30-something student, surnamed Oh, faces charges of benefiting the enemy and violating aviation safety and military installation laws by flying drones to North Korea four times from September to January. The incident became known after Pyongyang claimed last month that South Korea had infringed on its sovereignty with drone incursions in September and January. During the hearing at the court, Oh claimed he was not directed by anyone to send the drones, denying suspicions of links to the military intelligence command. The charge of benefiting the enemy also applies to cases where the military interests of one's own nation are harmed, and Oh's claim appeared aimed at disputing the notion that he harmed South Korea's military interests by stoking tensions with the North