Korean-American missionary Jun Young-su was arrested and interrogated in North Korea last November for a crime against the regime, the official KCNA news agency reported on Thursday. The report came only a day after the U.S. State Department released a statement about his detention.

The KCNA claimed Jun admitted the charge and the U.S. had been informed. The news agency also said authorities are preparing to put him on trial but did not specify the charges or details of his arrest.

According to Korean neighbors in California, where he has lived for about 10 years, Jun took a keen interest in spreading the gospel in North Korea. In his 60s, he went to China and on to North Korea's Rajin-Sonbong special economic zone to carry out missionary work while operating a noodle and bread factory. His wife is reportedly in Seoul.

A South Korean security official said recent growing evangelical work in the North "has bright and dark sides." He expressed concern that missionaries are easy targets of the regime but their organizations' activities in the North Korea-China border area are of great help to defectors.

Several American citizens have been detained in the North since the Barack Obama administration was inaugurated, and three or four cases were linked to religion.

Aijalon Mahli Gomes (32) was arrested in January last year for missionary and human rights work there. The regime succeeded in getting former U.S. president Jimmy Carter to fly to Pyongyang to discuss his release.

The evangelical activist Robert Park (30) crossed the border into the North in December 2009 to call for human rights and freedom of religion there. He was released 43 days later after being forced to read out a statement recanting his mission that was apparently extracted under torture.

Prof. Cho Young-ki of Korea University said the North often takes American citizens hostage for use as bargaining chips. Rights activists or missionaries working in the border area "need to be cautious when there is friction in inter-Korean relations or U.S.-North Korea relations," he added.