Scores of copies of Anne Frank's Diary of a Young Girl in public libraries across Tokyo have been vandalised, sparking alarm amid a rightward shift in Japan's politics.
Pages in at least 250 copies of the diary or publications containing biographies on Anne Frank, Nazi persecution of Jews and related materials have been torn, the council of public libraries said on Friday.
More than a dozen books have also been damaged at libraries in two other nearby areas, media reported.
"We have complaints from five of (Tokyo's 23) wards so far, but I don't yet know exactly how many libraries are affected," said Satomi Murata, the head of the council.
"We don't know why this happened or who did it."
The Simon Wiesenthal Center, the US-based international Jewish rights group, said on its website it was shocked and concerned.
"The geographic scope of these incidents strongly suggests an organised effort to denigrate the memory of the most famous of the 1.5 million Jewish children murdered by the Nazis in the World War II Holocaust," Abraham Cooper, the centre's associate dean, said in a statement.
"Only people imbued with bigotry and hatred would seek to destroy Anne's historic words of courage, hope and love in the face of impending doom.
"We are calling on Japanese authorities to step up efforts to identify and deal with the perpetrators of this hate campaign."
The diary, written by a Jewish girl who lived in Amsterdam during the time of the Holocaust, was added to the United Nations Education, Scientific and Cultural Organisation's Memory of the World Register in 2009.
Yasumi Iwakami, a freelance journalist who writes on social causes in Japan, tweeted there had been sporadic "delusional" arguments about the existence of a Jewish conspiracy surrounding the Holocaust.
"But violence has not presented itself to this extent before," he said, calling the incidents the "advent of crude anti-Semitism".
The spree comes amid criticism of a rightwards shift in Japanese politics under nationalist Prime Minister Shinzo Abe, with a recent volley of provocative comments about Japan's wartime past that have sparked accusations of revisionism by China and South Korea.
Largely homogenous Japan does not have a large Jewish community. The vast majority of people believe in Buddhism and indigenous Shintoism.
