Hundreds of suspected North Korean defectors in China have been deported to their country, Seoul's unification ministry said Friday, confirming claims made by multiple rights groups.

The South Korean daily Chosun Ilbo cited rights groups in reporting that Beijing had repatriated about 600 North Koreans on the night of 9 October.

Human Rights Watch separately said Beijing had "forcibly returned" more than 500 North Koreans to their home country.

Under a 1986 bilateral border protocol of Beijing and Pyongyang, North Koreans are not permitted to seek asylum or resettlement in China, and are instead deported back, according to HRW.

Ministry spokesperson Koo Byoung-sam told reporters in Seoul that the government raised the issue seriously with China.

South Korea's "position is that under no circumstances should North Korean defectors living abroad be forcibly repatriated to North Korea against their free will," he said.

Chinese foreign ministry spokesperson Wang Wenbin on Thursday declined to address specific deportation claims, saying there was "no such thing as so-called 'North Korean defectors' in China."