Kim Hak Song, who was working for the Pyongyang University of Science and Technology, was held on Saturday, Yonhap said, citing the state-run Korean Central News Agency.
Another US citizen was arrested at Pyongyang airport about two weeks ago for allegedly attempting to overthrow the North Korean regime.
Kim Sang Dok, an American citizen and professor, was visiting the Pyongyang University of Science and Technology on invitation, when he was intercepted at the airport before he could leave the country.
The arrests come as tensions rise between Pyongyang and Washington over North Korea’s nuclear and missile programmes.
Under leader Kim Jong Un, North Korea has ramped up its programmes, carrying out two nuclear tests and launching some 20 ballistic missiles last year alone.
At least 14 US citizens have been detained in North Korea over the past decade.(dpa/NAN)