North Korea this spring subjected abductees to mass ideological education on the superiority of the North's regime, according to the head of a group of victims' families.

While South Koreans make up the vast majority of the abductees, Choi Song Yong, quoting a source in Pyongyang, said those subjected to the lessons included Japanese.

It is unclear whether they included any of the 12 Japanese who Tokyo officially believes were kidnapped by the North in the 1970s and 1980s and remain missing.

Mass ideological education of abductees was carried out in the North until the 1980s. Kim Jong Un, the North's current leader, has ordered the education to resume, Choi said, citing his Pyongyang source.

There is a possibility that the resumption signals a change in the North's stance on Japan regarding the abduction issue.

Those who received the education consisted of about 60 South Koreans, including five former soldiers taken prisoner in the 1950-1953 Korean War, and about 20 foreigners, including Japanese, Choi said.

The people were divided into groups and received lessons in Pyongyang for about 15 days starting in late March. They also submitted documents saying they were in the North of their own free will and pledging allegiance to the North Korean system, Choi said.

Five Japanese abductees were returned to Japan in 2002, but several hundred are listed as those who may have been abducted by North Korea.