Teachers’ groups have protested Japan’s decision to state the Dokdo islets as Japanese territory in a teaching guide.

The Korean Teachers and Education Workers' Union said the Japanese decision was an intolerable provocation to the nation.

The union added that the guideline was expected to directly affect new Japanese textbooks and have serious aftereffects.

Seoul Liberal Teachers Union also blasted Japan’s decision, referring to it as a declaration of war on the nation.

The group criticized what it called Japan’s invasive nature, stating that Tokyo was trying to teach its claim over the Dokdo islets to the next generation even though the Japanese government is well aware that the islets belong to South Korea.

The union called for strengthened history education and patriotism programs for Korean students.