Women in bloodstained death camp uniforms waved Israeli flags and men dressed as German officers posed with guns at Monday's regional carnival in the small town of Campo de Criptana in the Castile-La Mancha region, around 90 miles southeast of Madrid.
The Israeli Embassy in Spain said in a tweet that it condemned "the vile and disgusting representation trivializing the Holocaust" and "making fun of the six million Jews killed by the Nazis."
The Auschwitz Memorial museum tweeted: "Hard to describe: memory upside-down, far beyond vulgar kitsch, without any relevance, without reflection & respect."
The El Chaparral Cultural Association, the carnival troupe from nearby Las Mesas that organized the Holocaust-themed part of the parade, apologized in a statement on Instagram to anyone who had been offended and said it had canceled further parades it had planned in the region.
"An erroneous image of our club has been disseminated that, really, is not what we intended," it said. "We wanted to transmit a message of consideration and respect.
"We are against the genocide against the Jewish people, for whom we feel great admiration and respect and to whom we present our apologies."
The City of Campo de Criptana said in a statement that the association had promised "a tribute to the millions of people who unjustly died in the extermination that took place during World War II in Germany."
The city authorities added: "Once we saw the representation, we share the criticisms produced. If the initial objective was to commemorate the victims, it is clear that this has not been achieved."
It said the association was responsible, because the city council "does not have prior capacity to control or supervise the staging of all the groups participating in the parade."
The council said it "strongly condemned" the genocide of Jewish people by the Nazis and any "mockery or trivialization of the subject."
Stand With Us, a group dedicated to fighting anti-Semitism around the world, called it "outrageous" and "unacceptable," while the Catalan-Israeli Friendship Association said it was "even worse" than a Belgian carnival that took place on Sunday. The parade in the city of Aalst was removed from UNESCO's cultural heritage list in December because of a "recurrence of racist and anti-Semitic representations."
Spanish radio network Cadena SER reported that the local mayor, Santiago Lázaro, said: "I agree that the theme does not seem very carnivalesque. I do not think it will happen again."
The Israeli Embassy in Spain said in its tweet that "European countries must actively combat anti-Semitism."
Human Rights Watch warned last June that "evidence of rising anti-Semitism in Europe has become impossible to ignore," after a Jewish cemetery in France was vandalized, Germany faced a spike in attacks on Jewish people and the United Kingdom launched a formal investigation into anti-Semitism in the Labour Party.