Russian President Vladimir Putin on Saturday addressed the nation about the Crocus City Hall shooting, denouncing it as a “bloody and barbaric” terrorist attack and vowing to punish all involved. At least 115 people have been killed and over 120 wounded in Friday evening’s massacre.

In his video address, the president declared a national day of mourning on Sunday, March 24, to commemorate the victims of the attack.

Putin expressed his gratitude to all first responders, to law enforcement, and to ordinary citizens, too, who helped the victims of the attack. At the same time, the president stressed another effort is underway, focused on the prevention of any further attacks.

”In Moscow and Moscow Region, in all regions of the country, additional anti-terrorism and anti-saboteur measures have been introduced,” he announced, adding: “The main thing now is to prevent those who are behind this bloodbath from committing a new crime.”

Vowing to punish all conspirators behind Friday night’s attack, Putin noted that, so far, 11 suspects, including four perpetrators who directly participated in the shooting spree, have been detained. The attackers were caught fleeing “towards Ukraine, where, according to preliminary data, a window to cross the border was prepared on the Ukrainian side,” he added.

“All perpetrators, organizers and masterminds behind this crime will get just and inevitable punishment. Whoever they are, whoever guides them. I repeat: we will identify and punish everyone who stands behind the terrorists, who prepared this atrocity, this attack on Russia, on our people,” the president stated.

Crocus City Hall, in the town of Krasnogorsk in Moscow’s western outskirts, was attacked by gunmen on Friday evening. Just before a concert by Russian rock band Picnic, when the venue, which has an estimated capacity of 7,500, was nearly full. The attackers, armed with assault rifles, breached the venue entrances, shooting patrons at point-blank range then setting the building on fire, before fleeing the scene.