Mr Koizumi has tried to mend regional relations

The new book was written by the same group of nationalist historians.

South Korea's Civilian Movement for Correction of Japanese Textbooks, a network of 80 civic and social groups, has called the book "a resurrection of Japanese militarism".

It said Asian countries would react "sternly" to Japan's approval of the books, especially since regional ties have been improved since last year's tension.

That tension was considerably raised last August when Japanese Prime Minister Junichiro Koizumi visited Tokyo's controversial Yasukuni war shrine, which honours convicted war criminals among the dead.

The visit sparked outrage from China and South Korea, who had both urged him not to go ahead with it.

Disputed island

Mr Koizumi then spent months trying to get relations back on track. During visits to both countries in October he apologised for Japan's wartime aggression in the 1930s and 1940s.

Yasukuni shrine honours 2.5m war dead, including 14 war criminals

Mr Koizumi is visiting China later this week.

One point of contention in the new book is that it says a small uninhabited island claimed by South Korea and Japan is historically part of Japan.

To strengthen its claim, South Korea keeps a small detachment of police officers on the island which is called Tok-do in Korean and Takeshima in Japanese.

"We express regret that the Japanese textbook does not correctly describe history with a neighbouring country," said Shin Jung-seung, a spokesman for South Korea's foreign ministry.

The books approved last year are being used in schools from this month, while the new book will come into use in the academic year starting next April.

The new book was one of 387 textbooks covering various subjects that were approved by the education ministry on Tuesday.