Twenty-one North Koreans were found in a boat that floated into South Korean waters earlier this week in the Yellow Sea, the largest such arrival in nine months.
The arrivals were being questioned, and it wasn't yet clear how or why the North Koreans arrived in South Korean waters. The South's long-standing policy has been to allow in North Koreans who choose to defect and repatriate those who wish to return, but defections are a sore point in Korean relations.
The boat was found off the northwestern island of Socheong and was handed over to the navy, a South Korean coast guard official in the port city of Incheon said.
The official couldn't provide more details because authorities were still questioning the North Koreans. He declined to be identified because he wasn't allowed to speak to the media until a public announcement was made.
South Korea's National Intelligence Service declined to comment, and neither Unification Ministry nor Joint Chiefs of Staff officials answered phone today.
The arrival was the largest of its kind since February, when 31 North Koreans floated south on a boat in the Yellow Sea. Seoul repatriated 27 of them and let the others say.
North Korea accused the South of holding the four against their will, which South Korea denies.
North Korea has yet to show any response over the latest arrivals.
Boats carrying North Koreans have occasionally drifted south of the Yellow Sea line dividing the Koreas, both accidentally and in deliberate attempts to defect.
In June, North Korea reacted angrily when South Korea refused to send back a group of nine it said were defecting.
More than 21,000 North Koreans have fled south since the Korean War ended in 1953, with defections surging in recent years as the North struggles with economic hardship and chronic food shortages.
High animosities between the Koreas have shown sings of easing recently as their diplomats have held talks aimed at resuming stalled negotiations on the North's nuclear weapons program.
The Koreas' ties badly frayed last year because Seoul blames Pyongyang for two attacks that killed 50 South Koreans.