The United Nations has apologised after a Serbian choir performed a song linked with the 1995 Srebrenica massacre to UN Secretary-General Ban Ki-moon.
"We sincerely regret that people were offended by this song which was not listed in the official program," UN spokesman Martin Nesirky said in reaction to protests over the singing of March to the Drina in a concert at the UN General Assembly on Monday.
Unaware of the song's nationalist connotations, Ban and other top UN officials gave the Viva Vox choir a standing ovation after they performed March to the Drina as their encore at the concert.
March to the Drina was originally written in praise of Serbian troops killed during a World War I battle, but has become a nationalist anthem for Serbs.
The words include phrases such as "blood was streaming by the Drina ... for Freedom".
March to the Drina was reportedly sung by Serb forces during the 1995 massacre in the Bosnian city of Srebrenica in which more than 8000 Muslim men and boys were slaughtered.
The Drina is Bosnia's longest river and passes through Srebrenica, which was officially under UN protection at the time of the massacre, now considered one of the darkest chapters in UN peacekeeping history.
"We are aware that some people were offended by the encore song at the concert...," Nesirky told reporters.
"The secretary-general was obviously not aware what the song was about or the use that has been made of it in the past."
The concert to mark the Orthodox New Year at the UN headquarters was organised by Vuk Jeremic, the former Serbian foreign minister and current president of the UN General Assembly.
In a statement Jeremic said: "With solemn respect for all the victims of the tragic wars in former Yugoslavia, this is a highly regrettable attempt at twisting the meaning of our musical gift offered to the world this week, and (a) deeply offensive one for the Serbian people."
"We are very proud of it, and we wanted to share it with the world with a clearly stated accompanying message of reconciliation for present and future generations."