The Tokyo Prefecture Teachers' Union says there are no historical grounds for Japan to claim sovereignty of the Dokdo islets in the East Sea.

The Japanese daily Sankei Shimbun reported Friday the teachers’ union of elementary, middle, and high school teachers in Tokyo Prefecture made the statement after conducting a comparative study on four Japanese geographic textbooks for middle school students.

In a report based on the study, the union raised the concern that students will be exposed to emotional nationalism if the Japanese government’s unilateral claim is taught at school.

Japan has been claiming that Dokdo is part of Japan’s territory and illegally occupied by South Korea. The teachers’ union’s position runs counter to the Japanese government’s claim to the islets.