A Japanese daily newspaper has apologised for carrying an advertisement for books by an author who claims Jewish people were behind the country's 2011 earthquake-tsunami disaster. The advert ran in a regional edition of the conservative Sankei Shimbun on November 26, and promoted the works of Richard Koshimizu, a self-styled journalist and activist who also blames Jews for the September 11 attacks in the United States. The little-known Koshimizu used the space to advertise a book claiming the US is a "Jewish dictatorship state" that detonated an atomic bomb deep under the sea to trigger the earthquake and subsequent tsunami. It was intended to destroy the Japanese economy and defend the dollar, he claimed. In a published apology, the newspaper's president Takamitsu Kumasaka wrote: "It is extremely regrettable that an advertisement of this content was carried and delivered to our readers, and we deeply apologise to readers and the people of the Jewish community." "It was obvious there was a fault in our screening of advertisements," he said. The March 2011 natural disaster sparked the Fukushima nuclear plant meltdown and left 18,000 people dead or missing. In another book featured by the advertisement, Koshimizu claims the Holocaust was a "fabrication" designed to establish the state of Israel. Kumasaka added he had received a letter of protest from Abraham Cooper, associate dean of Jewish rights group the Simon Wiesenthal Center, over the advert. "The Sankei considers the Holocaust by the Nazis as an unforgivable, heinous crime," the president said. The Sankei said the ad was in the Tokai/Hokuriku edition covering central Japan, which has a circulation of just 5,000 copies.