Scores of copies of Anne Frank's The Diary of a Young Girl in public libraries across Tokyo have been vandalised, increasing fears about a shift to the right in Japanese politics.
Pages were ripped out of at least 250 copies of the diary or publications containing biographies of Anne Frank or details of the Holocaust, the council of public libraries in the capital said.
More than a dozen books were also damaged at libraries in two nearby areas.
Chief Cabinet Secretary Yoshihide Suga called the vandalism "shameful" and said Japan would not tolerate such acts.
Satomi Murata, head of the libraries council, said: "We have complaints from five of [Tokyo's 23] wards so far, but I don't yet know exactly how many libraries are affected."
Kaori Shiba, the archives director at the central library in Shinjuku ward, where 39 books were vandalised at three libraries, said: "Each book had 10-20 pages torn out, leaving it unusable."
Toshihiro Obayashi, deputy director of the central library in Suginami, said 119 books were damaged at 11 of the area's 13 public libraries. "Each and every book which comes up under the index of Anne Frank has been damaged at our library."
Anne Frank wrote her diary over the two years she and her family hid in a concealed apartment in Nazi-occupied Netherlands during the second world war. After her family was betrayed and deported, she died in a German concentration camp at age 15 in 1945. Her father survived and published her diary, which has become the most widely read document to emerge from the Holocaust.
Japan and Nazi Germany were allies in the war, and though Holocaust denial has occurred in Japan at times, the motive for damaging the books is unclear. Police are investigating.
The Simon Wiesenthal Centre, the US-based international Jewish rights group, said it was shocked. "The geographic scope of these incidents strongly suggest an organised effort to denigrate the memory of the most famous of the 1.5 million Jewish children murdered by the Nazis in the Holocaust," said Abraham Cooper, the centre's associate dean. "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."
Yasumi Iwakami, a 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".
The vandalism comes amid criticism of a rightwards shift in Japanese politics under nationalist Prime Minister Shinzo Abe. Provocative comments about Japan's wartime past have brought accusations from China and South Korea of revisionism.
Additional reporting by Associated Press