People have been laying flowers at the Russian embassy in Yerevan, Armenia to honor the memory of the victims of the March 22 deadly terror attack in Moscow, which left at least 115 people killed and 121 wounded.

Video footage from the Crocus City Hall shows the vast complex, which is home to both the music hall and a shopping center, on fire with smoke billowing into the air. State-run RIA Novosti reported the armed individuals “opened fire with automatic weapons” and “threw a grenade or an incendiary bomb, which started a fire.”

Russia’s Investigative Committee said four men suspected of carrying out the attack had been taken into custody while trying to cross Russia’s border with Ukraine.