The ministry in charge of inter-Korean affairs says China appears to have repatriated a number of North Koreans back to the communist state.

Unification ministry spokesperson Koo Byoung-sam said on Friday that while it seems that many North Koreans in China's three northeastern provinces were repatriated, it is unclear exactly how many there were and which were defectors, patients or criminals.

Koo said Seoul stands by its position that North Korean defectors should not be repatriated against their will under any circumstance.

Expressing regret over the situation, the spokesperson said Seoul has sternly taken the issue up with Beijing and highlighted its position.

On Wednesday, the Seoul-based Justice for North Korea claimed that over 600 North Korean defectors that were detained in China's border regions were repatriated to the North through cities of Dandong and Hunchun Monday night.