Russian flags at half-mast in Moscow following concert hall attack

Russia lowered flags to half-mast on Sunday in Moscow, as the country mourns people that were killed in a terrorist attack at a concert hall in northwestern Moscow Oblast on Friday.　

Images of candles were displayed on electronic screens to mourn for the victims of the attack.　

Russian President Vladimir Putin announced March 24 as the day of national mourning after vowing to track down and punish those behind the "barbaric terrorist attack."　

(Reported by Tian Bing; Edited by Ma Yuxuan)