The Dokdo Research Institute under the Northeast Asian History Foundation has unveiled three Japanese maps that mark the Dokdo islets as Korean territory.

The institute on Wednesday unveiled the maps in an emergency symposium on Japan’s recent approval of high school textbooks laying claims to Dokdo.

The maps, including two drawn in 1892 and 1895, marked Dokdo and Ulleung Island in light purple, which is the same color used to mark Gangwon Province of Korea. The color, however, was not used to mark any regions of Japanese territory in the maps.

Lee Hoon, head of the institute, said that the maps show Japan’s claims to Dokdo in the high school textbooks are groundless.