South Korea has demanded the release of two of its citizens being held by the North on allegations of spying. Seoul has also denied that the two men were involved in espionage operations against the North.
South Korea's Unification Ministry confirmed the identities of the two men in question, and demanded that North Korea immediately return them.
"We strongly demand that North Korea quickly releases our citizens Kim Kuk Gi and Choe Chun Gil and repatriate them without hesitation," Lim Byeong Cheol, a spokesman for the ministry, told reporters at a press conference in Seoul.
At the same time, South Korea's National Intelligence Service denied that the two men had been spying on North Korea.
Earlier, Pyongyang's official Korean Central News Agency (KNCA) said Kim had been arrested in Pyongyang in September, while Choe had been detained near North Korea's border with China in December.
The two suspects were presented to reporters and foreign diplomats at a press conference in Pyongyang.
Distributing comic books and religious propaganda
The KNCA said Kim had confessed among other charges to distributing comic books critical of Pyongyang. He was also accused of spreading "religious propaganda" from an "underground church that he ran in the Chinese border town of Dandong. Chloe, meanwhile, is reported to have admitted to smuggling CDs and USB memory sticks containing pornographic films and South Korean movies into the North. The KNCA described both as "heinous terrorists."
North Korea has from time to time detained South Koreans or other foreigners in the past, forcing them to admit to wrongdoing in state media, before retracting their confessions following their release.
The latest arrests come amid annual military drills involving South Korean and US military forces, which Pyongyang regards as preparation for an invasion. Both Seoul and Washington insist that they are strictly of a defensive nature.
pfd/sms (AP, AFP, dpa)