PYONGYANG, May 3 (Xinhua) -- The Democratic People's Republic of Korea (DPRK)on Wednesday confirmed the arrest of a U.S. citizen last month for allegedly carrying out hostile action aimed at toppling the Pyongyang government in the past and now.

The official Korean Central News Agency said the "relevant institution of the DPRK intercepted American citizen Kim Sang Dok at Pyongyang International Airport at 08:00 a.m. April 22 (2300 GMT April 21) under a relevant law of the DPRK."

"Invited to Pyongyang University of Science and Technology to teach accounting as a professor, he was intercepted for committing criminal acts of hostility aimed to overturn the DPRK not only in the past but also during his last stay before interception," said the news agency.

"Kim is now under detention by a relevant law enforcement body which is conducting a detailed investigation into his crimes," it said.