Images of North Korea’s former leaders, Kim Jong-il and Kim Il-sung, in the capital, Pyongyang

North Korea has detained another American citizen, reports Reuters.

Korean-American Tony Kim was arrested on Saturday (22 April) at Pyongyang International Airport as he was trying to leave the country.

He had spent a month teaching accounting at Pyongyang University of Science and Technology (PUST).

The university’s chancellor, Chan-Mo Park, said: “The cause of [Kim’s] arrest is not known but some officials at PUST told me his arrest was not related to his work at PUST. He had been involved with some other activities outside PUST such as helping an orphanage.”

PUST was founded by evangelical Christians and opened in 2010, with students generally the children of the country’s elite. Its volunteer faculty, many of whom are evangelical Christians, has a curriculum that includes subjects once considered taboo in North Korea, such as capitalism. According the Korean News Agency, Yonhap, Kim is a devout Christian.

Kim, who also goes by his Korean name Kim Sang-duk and is in his fifties, brings the total number of Americans held by North Korea to three. Kim Dong Chul, a 62-year-old Korean-American missionary, was detained in 2015. Otto Warmbier, 22, arrested in 2016, was given 15 years’ hard labour following his “confession” that he’d stolen a piece of political propaganda at the request of his church.

Korean-Canadian pastor Hyeun-soo Lim was given a life sentence in 2015 for various charges, including trying to overthrow the government. Like Tony Kim, Lim was involved in humanitarian work with orphanages.