Russian President Vladimir Putin has called on authorities to do everything necessary so that the perpetrators of a recent massacre at a concert hall in the Moscow region will be punished.
In his address to the Prosecutor's Office on Tuesday, Putin said he believes the authorities will do everything "to ensure the Friday Moscow shooting participants receive a fair punishment."
"They (investigators) are uncovering details, determine the role and degree of guilt of each participant, study the conclusions of criminologists and experts," he said at a meeting at the General Attorney's Office board in Moscow.
"I hope that the attorneys, within the limits of their powers, including at the presentation of state charges and during the trial, will do everything necessary to ensure that the criminals are fairly punished, as required by Russian law."
The National Anti-Terrorist Committee is coordinating the work of different intelligence services engaged in the investigation, he said.
Russia's Prosecutor-General Igor Krasnov has said punishment is inevitable for those behind the attack and those who carried it out.
The chief of the Russian internal intelligence (FSB) Alexander Bortnikov recently accused Ukraine of "training the fighters [suspected in the attack] in the Middle East."
"The United States, United Kingdom and Ukraine are behind the attack," Bortnikov said.
The Russian Federal Security Service said the gunmen responsible for the attack planned to travel to Ukraine, where they were to be welcomed as “heroes.” The FSB said Western intelligence services aided the attackers.
Four gunmen burst into Moscow’s Crocus City Hall on March 22 and began shooting at the people who attended an event. They killed nearly 140 people and injured over 180 others.
Eleven people, including the assailants, have been detained and are facing terrorism charges.