Japan has approved additional high school social studies textbooks which claim South Korea’s Dokdo Islets as Japanese territory.

Japan’s Ministry of Education, Culture, Sports, Science and Technology held a textbook screening committee meeting on Tuesday and approved 21 high school textbooks, 15 of which described Dokdo as being part of Japanese territory.

Among Japanese high school textbooks approved this year and last year, 37 of 50 social studies-related textbooks include Japan’s territorial claims over Dokdo.

All geography textbooks described Dokdo as Japanese territory, while nine out of 12 history textbooks include descriptions on sex slaves during World War Two.

The South Korean government said it will sternly deal with Japan’s approval of textbooks that lay claim to Dokdo.