There was shock and mourning on the streets of the capital on Sunday.
“It is a tragedy. I was morally crushed,'' Ruslana Baranovskaya, 35, told AFP.
“People don't smile… everyone feels the loss,” said Valentina Karenina, a 73-year-old pensioner standing on a street near Red Square, next to the Kremlin in the center of Moscow.
Museums, theaters and cinemas across the country were closed and billboards were replaced with commemorative posters.
Mourners continued to flock to a concert hall in northwest Moscow to pay tribute to the victims.
Officials said more than 5,000 people donated blood after the attack, many of whom stood in long queues outside clinics.
Putin on Saturday vowed to deliver “retribution and oblivion” to “terrorists, murderers and non-humans” who carried out the “barbaric, terrorist attack”.