North Korea has arrested two South Korean men on the charge of espionage for the South's state spy agency, according to Pyongyang's media.

The North held a press conference of the two, which it identified as Kim Kuk-gi and Choe Chun-gil, in Pyongyang on Thursday, reported the communist nation's state-run Korean Central News Agency. Domestic and foreign reporters attended it, added the KCNA.

An unnamed official at the North's Ministry of State Security branded them as "spies" of the South's National Intelligence Service and "heinous terrorists."

"They zealously took part in the anti-DPRK (North Korea) smear campaign of the U.S. imperialists and the puppet group of traitors to isolate and blockade the DPRK in international arena by labeling it 'a country printing counterfeit notes' and 'sponsor of terrorism' while pulling it up over its 'human rights issue,'" the North's official was quoted as saying.

DPRK is the acronym for the Democratic People's Republic of Korea, the North's official name.

The official also accused the two of gathering information on the Workers' Party of Korea and other state and military secrets.

The North released details of their personal backgrounds.

Kim was born in Daejeon, a South Korean city, and he used to operate an underground church in the Chinese border city of Dandong, the North said.

It said Choe's hometown is the South's eastern city of Chuncheon, and the 56-year-old left his country in 2003 and spent many years in China. (Yonhap)