A Jewish human rights organisation has called on Thai Christian leaders to condemn the Nazi-themed parade at the Sacred Heart Preparatory School in Chiang Mai where students were seen dressed up as Adolf Hitler and SS guards doing "seig heil" salutes.

Students dressed as Nazi SS guards with swastika armbands walk in a parade to mark a sports day last Friday at the Sacred Heart Preparatory School in Chiang Mai’s Muang district. The parade drew an angry public response and the school has apologised.

The Simon Wiesenthal Center, an international Jewish human rights group based in Los Angeles, issued a statement on Monday denouncing an event it said was "glorifying Nazis".

Images of the event show a girl dressed up as Adolf Hitler, complete with toothbrush moustache, leading a parade consisting of youngsters carrying a Swastika flag and another group dressed up in Nazi uniforms with plastic guns to complete the look.

Rabbi Abraham Cooper, associate dean of the Simon Wiesenthal Center, insisted that from the visuals, it was clear that this Nazi celebration could not have taken place without the knowledge and cooperation of the school administration.

Rabbi Cooper called on the school to take immediate action against people responsible for "promoting and facilitating this disgraceful display".

"It is difficult to calculate the hurt such a display inflicted on survivors of the Nazi Holocaust and the families of all victims of Nazism. There can be no justification for such an outrage to emanate from a place of learning," he said.

Rabbi Cooper, a frequent visitor to Asia, added that a similar parade took place in 2007 at a school in Bangkok involving 200 students and, more recently, Thai rock band Slur donned Nazi regalia in a music video.

British Embassy in Thailand spokeswoman Kim Clarke only confirmed that a group of honorary consuls went to the school to seek an explanation about the event.

Yesterday, Sacred Heart College Chiang Mai expressed its deep apologies for its pupils dressing up in the Nazi outfits and marching in the event.

Chanwit Tubsuphan, secretary-general of the Office of the Private Education Commission (Opec), said the director of Sacred Heart College in Chiang Mai had expressed regret and apologised for the incident.

The event was harshly criticised after photographs taken on the sports day were posted online.

The commission ordered the Chiang Mai Educational Service Area which supervises the school to look into the case and the Chiang Mai education unit reported later that the school's teachers were not informed about the students' theme for the sports day event prior to it taking place, Mr Chanwit said.

The students also did not realise that using the Nazi theme had any sensitive or negative implications.

"The students feel alarmed by the response, as they had no intention to express any hidden agenda and the teachers are sorry for what their students did," Mr Chanwit said.

Traditionally, the students wear fancy dress in the parade on sports day and the theme is kept a secret until the day itself, with the most recent one held last Friday.

"So, the teachers were not informed about the plan," he explained.

The secretary-general said the school will send a letter to explain and clarify the event to the Opec soon.

"It happened because the students were unaware and I have asked the school to make sure they are more careful [in future]."

Mr Chanwit said lessons on the history of World War II have already been provided to the children and it was one of eight core subjects in social sciences designed by the Education Ministry.

The Bangkok Post tried to call the school principal to discuss the Nazi theme controversy yesterday but a school staff member would not put the principal on the phone.

The staff member only said it was a sports day and the event's theme was managed by the students.