TOKYO -- Japan risked further irking their close neighbors China and South Korea on Tuesday, when the government announced textbooks were being changed to make it clear that two sets of remote islands at the center of sovereignty disputes are integral parts of their territory.
Education Minister Hakubun Shimomura said the ministry was revising the teaching manuals so junior high and high school students learn "properly" about Japanese history and to make it clear that there is no dispute over the ownership of the rocky Senkaku islands in the South China Sea.
The island chain that China calls the Daioyus, have been a flash point between the two countries since Tokyo nationalized the group of uninhabited archipelagos in 2012.
China claims almost all the South China Sea and in November announced it was expanding its air defense identification zone to include the disputed islands.
A few days after they began to enforce this, American bombers flew over the islands on what was described as a training mission.
South Korea summoned the Japanese ambassador on Tuesday to protest claims to the Takeshima islets, known as Dokdo in South Korea. They are situated most equidistant between the two countries.
"Our government strongly condemns this and asks Japan to immediately withdraw it," Seoul, who have administered the islets since the end of World War II, said in a statement.
Previously, Japanese textbooks only made reference to the opposing positions of the countries.
Japan's ties with Seoul and Beijing are increasingly strained over a host of issues, including the territorial rows and Japanese Prime Minister Shinzo Abe's visit late last year to the Yasukuni Shrine, where convicted war criminals are honored along with millions of war dead.
Both China and Korea suffered under Japanese rule, with parts of China occupied in the 1930s and Korea colonized from 1910 to 1945.
Henry Austin reported from London. Reuters contributed to this report.