TOKYO (REUTERS) - A Japanese school board's bid to limit children's access to a classic anti-war comic has sparked an outcry from those who fear the move is part of a trend to whitewash the country's wartime past.

The furore, which grabbed headlines this week, echoes concerns about Prime Minister Shinzo Abe's conservative agenda to recast Japan's wartime history in a less apologetic tone.

Mr Keiji Nakazawa's manga, "Barefoot Gen", is based on the author's own experience of the Aug. 6, 1945 atomic bombing of Hiroshima, and tells of the struggle of a boy whose father and siblings were killed.

Published over a dozen years from 1973 and translated into some 20 languages, the comic includes harsh criticism of the late Emperor Hirohito in whose name Japan fought World War Two.

Besides its stark depiction of the aftermath of the bombing, the 10-volume manga graphically illustrates atrocities by Japanese soldiers in Asia.

"It's the only manga in school libraries ... Many people remember the experience of stumbling across it and reading it and it having an impact," said Mr Koichi Nakano, a political science professor at Sophia University.

The move to limit access, he added, "comes across as part of a trend to purify the more horrifying narrative of the war."

The debate caught fire last week after domestic media reported that a school board superintendent in western Matsue City had asked primary and middle schools to take the comic off library shelves.

Because of the manga's graphic violence, students would have to get permission to read it, according to the December directive, which followed a request from local citizens, media said.

"The education board's decision could deprive children of a good opportunity to learn about the tragedy," the Asahi newspaper said in an editorial this week.

"There is no need to keep children from accessing this material."

Japan's manga culture spans the gamut from cute to violent and pornographic but most are for entertainment, not education.

A classic that has been made into movies and animated films, the comic has drawn criticism from Japanese ultra-conservatives.

Such conservatives also argue that Japan's post-war education system has taught a "masochistic" account of history that puts too much stress on the country's wartime misdeeds.

Mr Abe raised eyebrows last week when he omitted any reference to "remorse" for suffering caused by Japan's past military aggression in Asia from his speech at a ceremony marking the Aug. 15 anniversary of the country's defeat in World War Two.

Education Minister Hakubun Shimomura told a news conference this week he saw no problem with the decision to limit access.

"I don't think this violates freedom of expression," he said in remarks carried by broadcaster NHK.

Mr Noriyuki Masuda, an official of the Hiroshima Peace Memorial Museum, which is now running an exhibition of the manga, declined to comment on the action by the Matsue school board, which is set to meet on Monday to reconsider the directive.

But he said many parents had brought their children to the exhibit.

"The atomic bombing was inhumane, and I think that this manga depicts the tragedy that occurred, which was a fact,"Masuda told Reuters by telephone.

"I think it is useful for deepening understanding of that."