Close to 20,000 children of foreign nationality in Japan may not be attending school despite being eligible to enroll, a government study showed Friday.

The first such survey conducted by the education ministry in May and June found that 19,654, or 15.8 percent, of eligible foreign children, are not attending Japanese elementary or junior high schools, although some may be going to international schools.

According to the ministry, foreign children who wish to attend Japanese public elementary or junior high schools can do so free of charge under the International Covenants on Human Rights and other agreements. However, unlike Japanese children, education for them is not compulsory.

In accounting for the lack of attendance, the ministry said some children and guardians may not have sufficient command of the Japanese language and local government support also varies, adding that some children may be working or looking after siblings at home . . .