As Russia continues to grapple with the aftermath of the deadly concert hall attack that claimed 139 lives and injured more than 180 people, Health Minister Mikhail Murashko revealed on Tuesday that 22 victims, including two children, remain in serious condition. The update comes as President Vladimir Putin admitted that "radical Islamists" were behind the massacre but maintained his accusation that Ukraine could have played a role in the attack, despite evidence pointing to the involvement of the Islamic State.

The attack, which took place on Friday night at the Crocus City Hall music venue on Moscow's western outskirts, was one of the deadliest in Russia in years. Four men, identified as citizens of Tajikistan, have been charged with committing a terrorist attack resulting in the death of others, an offense that carries a maximum sentence of life imprisonment. The suspects, named as Dalerdzhon Mirzoyev, 32; Saidakrami Rachabalizoda, 30; Shamsidin Fariduni, 25; and Mukhammadsobir Faizov, 19, appeared before a Moscow court on Sunday, showing signs of severe beatings, with one barely conscious during the hearing.

Russian officials said they detained a total of 11 people in connection with the attack, including Alisher Kasimov, a citizen of Kyrgyzstan, who was charged on Monday with renting an apartment to the accused attackers. A senior Turkish security official confirmed that two of the suspects, Fariduni and Rachabalizoda, had spent a "short amount of time" in Turkey before traveling together to Russia on March 2, but believed they had become radicalized in Russia due to their brief stay in Turkey.

Two days after the Islamic State's Afghanistan affiliate, ISIS-Khorasan, claimed responsibility for the attack, Putin acknowledged during a meeting with government officials that the killings were carried out by extremists "whose ideology the Islamic world has been fighting for centuries." However, he continued to suggest that Ukraine could have been involved, stating, "We know by whose hand the crime against Russia and its people was committed. But what is of interest to us is who ordered it."

France joined the United States on Monday in blaming the Islamic State for the attack, with President Emmanuel Macron stating, "The information available to us...as well as to our main partners, indicates indeed that it was an entity of the Islamic State which instigated this attack." Macron noted that the group had also attempted to carry out several actions on French soil, including the massacre of 90 people at a Paris concert hall in November 2015.

Ukrainian President Volodymyr Zelenskyy dismissed Putin's accusations, saying, "What happened in Moscow yesterday is obvious, and Putin and other scums are trying to shift the blame to someone else. Their methods are always the same."

The U.S. embassy in Moscow had warned of a possible attack on March 7, issuing a public advisory that it was "monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to include concerts." Despite this warning, Putin accused the U.S. of "using different channels to try and convince its satellites and other countries of the world that, according to its intelligence, there is supposedly no sign of Kyiv's involvement in the Moscow terrorist attack."

Unverified videos of the suspects' interrogations circulated on social media, with one suspect shown with part of his ear cut off and stuffed into his mouth. Kremlin spokesman Dmitry Peskov declined to comment on the treatment of the detainees when questioned by reporters.