Japanese Education Minister Hakubun Shimomura on Tuesday announced that the ministry has revised the country's teaching manuals for junior and senior high schools to claim areas in disputes between Japan and China and between Japan and South Korea, according to local media.

The minister said in a press conference that it is natural for Japan to teach "properly" about its territory, adding that his ministry is working with Japan's foreign ministry on the territorial issues.

The new manuals will describe the disputed territories as " Japan's integral parts," according to Japan's Kyodo News.

Relations between Japan and China have frayed since it illegally "nationalized" the Diaoyu Islands, which are inherent territories of China, in September 2012.

Tokyo and Seoul are also at odds over a pair of rocks in the Sea of Japan. The islets are known as Dokdo in South Korea and Takeshima in Japan.

The manuals will be used for textbooks for junior high school social studies and senior high school geography, history and civics classes, said Kyodo. The country earlier this month revised textbook screening guidelines.

It is unusual to revise the manuals at this time as they are usually revised every 10 years along with the amendment of curriculum guidelines, said Kyodo, adding that the existing teaching manuals for junior and senior high schools were published in 2008 and 2009 respectively.

Textbook revision issue is one of the obstacles between Japan and its neighboring countries as it reflects Japan's attitude toward its militarism past.

South Korea in 2008 briefly recalled its ambassador from Japan in protest after Japan revising the manuals and for the first time mentioning that the disputed territory with South Korea belongs to Japan.

On Tuesday, South Korea blasted again on Japan's move with the South Korean Foreign Ministry summoning Japanese Ambassador Koro Bessho and demanding Japan retract the manuals.

Meanwhile, China also logged stern protest against the move and urged Japan stop provocative actions and respect historical realities.