North Korea says it has detained another U.S. citizen, accusing him of committing "hostile acts."
The North's official news agency KCNA said Kim Hak Song was detained on Saturday. The report said he had worked for the Pyongyang University of Science and Technology, the only privately funded university in North Korea and a school that is also unusual for the large size of its foreign staff.
In a statement, the U.S. State Department said, "The security of U.S. citizens is one of the department's highest priorities. When a U.S. citizen is reported to be detained in North Korea, we work with the Swedish embassy in Pyongyang" to try to secure their freedom.
Kim Hak Song is the fourth American citizen in North Korean custody and his detention comes as tensions increase between Pyongyang and Washington over North Korea's nuclear weapons development program. U.S. President Donald Trump has dispatched an aircraft carrier strike group to the waters off the Korean peninsula as a warning against the communist nation's military ambitions.
Last month, Pyongyang detained Kim Sang Dok, a Pyongyang University accounting professor in his 50s it accused of "acts of hostility aimed to overturn" the regime of the North Korean leader, Kim Jong Un. North Korea said Kim Sang Dok was arrested "for committing criminal acts," but did not elaborate.
In the case of Kim Hak Song, authorities said, "A relevant institution is now conducting detailed investigation into his crimes."
In a 2015 message on the website of a Korean-Brazilian church in Sao Paulo, Kim Hak Song said he was a Christian missionary planning to start an experimental farm at the Pyongyang school and was trying to help the North Korean people learn to become self-sufficient.
North Korea has in the past detained U.S. citizens to use as bargaining chips in its negotiations with Washington.
Last year, Otto Warmbier, a University of Virginia student, was sentenced to 15 years of hard labor in prison after he confessed to trying to steal a propaganda banner.
Kim Dong Chul, born a South Korean but believed to have U.S. citizenship, is serving 10 years of hard labor for subversion.