SEOUL (Reuters) - A package exploded at South Korea’s Yonsei University in central Seoul on Tuesday, injuring a faculty member who opened it in his office, police and fire officials said.

The faculty member, who was not identified, took a box that was in a shopping bag left at his office door and opened it in his office. The blast sent nails flying through the room, police said.

The engineering faculty member was not seriously injured, but was being treated in hospital for burns to his wrist and neck.

Police said in a statement that they were analyzing what the package, which they described as a “crude device”, and checking security cameras to determine who left it at the door.

The injured staffer was the only person in the office at the time, and no other faculty members or students are believed to be injured, a fire official said.