The talent agency that represents K-pop group BTS on Tuesday apologized over one of its members wearing an offensive T-shirt that depicted an atomic bomb exploding over Japan, and other members having earlier worn hats that carried the Nazi guard insignia.

In a statement, agency Big Hit Entertainment sincerely apologized for what happened and vowed to reach out to Japanese and Korean groups representing A-bomb survivors “in order to explain and apologize for the hurt caused.”

“We’d like to clarify that all Big Hit staff and artists, including BTS, do not regard war or atomic bombs lightly. We’re against these things, and we have no intention to hurt those who were victims of the atomic bombs.”

It said those involved “did not do appropriate research” before the artists wore the unintentionally hurtful clothing. “For this and to those who were uncomfortable with the imagery, we sincerely apologize,” it added.

Jimin, the BTS member who wore the controversial A-bomb T-shirt, told fans during the group’s concert at Tokyo Dome on Tuesday that “his heart really aches” about the incident, South Korea’s Yonhap News Agency reported.

Japanese TV broadcaster TV Asahi Corp. recently canceled a concert by the group amid the controversy over Jimin wearing the shirt in 2017 in celebration of Korean Liberation Day, which falls on Aug. 15.

The T-shirt displayed English words such as “Patriotism,” “Our History,” “Liberation” and “Korea,” with a black-and-white photo of a rising mushroom cloud and another of Koreans celebrating the end of Japanese colonial rule of Korea in 1945.

Earlier this week, an international Jewish human rights organization denounced BTS for “denigrating the memory of the past” after band members posed in 2015 for a photo shoot wearing hats featuring the Nazi SS Death Head logo. The Jewish NGO, called Global Social Action of the Simon Wiesenthal Center, also described the flags appearing on the group’s concert stage as “eerily similar to the Nazi Swastika.”Regarding that incident, the talent agency said it and BTS “do not regard Nazis lightly nor any other group that promotes ideals or totalitarianism or extremism.”

“We oppose these things, we have no intention to hurt those who were affected by the history of groups like this, and we will continue not have any such intention.”

“However, the fault of the above issues lie with the artists’ company Big Hit, which did not do its due diligence. We’d like to clearly emphasize that the company’s artists have no responsibility or relation to the above issues.”

It pledged to gain a better understanding of social, historical and cultural backgrounds “and be more cautious so as to avoid causing hurt to anyone.”

In a statement released Tuesday, the Jewish NGO welcomed the talent agency’s apology and said the BTS management would “personally be in touch” with the Jewish organization.

“The outrageous incidents reveal a basic lack of knowledge of history’s darkest chapters that endangers the future of younger generations,” said Rabbi Abraham Cooper, the NGO’s associate dean and director of global social action.

“We are reaching out to BTS and their management to urge that they harness their international fame to celebrate the good not serve the forces of evil,” he added.

BTS, also known as the Bangtan Boys, is a seven-member South Korean boy band that debuted in 2013. In May this year, the group reached the top of the Billboard 200 album chart with its new release “Love Yourself: Tear.”