Local media said mayor Gagik Beglaryan beat up presidential protocol aide Aram Kandayan the day after the Dec. 3 concert, because he had asked the mayor's wife to change seats after she sat next to the president.

A brief statement on the mayoral website confirmed Beglaryan, a senior member of Armenia's ruling Republican Party, had resigned from the top job in Yerevan, home to over a third of Armenia's 3.2 million people.

It gave no reason. A spokesman for Sarksyan told Reuters: "The president of Armenia has repeatedly stated that such behavior is unacceptable and intolerable, particularly in the case of public officials." Allegations of political violence, including attacks on opposition activists, continue to undermine the former Soviet republic's boast that it is building a European-style democracy in the volatile South Caucasus.