UNITED NATIONS (AP) — The United Nations apologized Thursday for the ovation given to a militant Serb nationalist song performed at a concert honoring Serbia’s presidency of the U.N. General Assembly, Secretary-General Ban Ki-moon’s spokesman said.

Martin Nesirky said that “the United Nations was aware that some people were offended by the song “March to the Drina,” sung in the General Assembly hall Monday night. Ban afterward stood at the podium alongside Vuk Jeremic, the former Serbian foreign minister and current assembly president, for a photo with the performers, the Belgrade vocal group Viva Vox.