The education ministry has issued a notice to boards of education across the country urging teachers not to use "inappropriate" supplementary learning materials, in the first move of its kind in decades.
The notice, issued Wednesday, comes in the wake of recent incidents in which teachers used images released by the Islamic State militants and a map that referred to the Sea of Japan also as the East Sea, as the body of water is known in South Korea.
It's the first time in 40 years the education ministry has issued a notice regarding supplementary teaching materials.