Ukraine's military intelligence (HUR) has said a deadly shooting on a concert hall in Moscow on March 22 is a "deliberate provocation by Putin's special services."
The attack – ongoing at the time of writing – saw several gunmen opening fire at the Crocus City Hall ahead of a concert.
Images posted to social media showed them walking unchallenged through the venue and firing indiscriminately at those inside.
According to Russia's Investigative Committee and the Russian Health Ministry, over 60 people were killed and more than 140 wounded following the attack.
"This is a deliberate provocation by Putin's special services, about which the international community warned," Andrii Yusov, a spokesperson of Ukraine's military Intelligence, told Ukrainska Pravda.
In a post on its Telegram channel, HUR claimed the shooting is intended to justify "even tougher" attacks on Ukraine and total mobilization in Russia.
"The public execution of people in Moscow should be understood as Putin's threat of an even greater escalation and expansion of the war," HUR wrote.
The terrorist group Islamic State (IS) later claimed responsibility for the attack in a Telegram post, and U.S. intelligence officials confirmed the claim.
On March 7, the U.S. Embassy in Russia issued a warning that "extremists have imminent plans to target large gatherings in Moscow" and urged American citizens to stay away from concentrations of people over the next 48 hours.
"The unimpeded movement of a group of militants with assault rifles through the center of Moscow, as well as a lot of other indisputable evidence, indicate that the shooting in Crocus City Hall was organized by the Russian special services," HUR wrote.
"International embassies also warned about the preparation of a terrorist attack."
In 1999 shortly after Vladimir Putin become president, a series of apartment bombings rocked Russia which were blamed on Chechen separatists, lighting the fuse for the second Chechen war.
Since then, speculation has continued that Putin and Russia's Federal Security Service (FSB) orchestrated the bombings to boost his popularity and legitimize the war.
Just hours after the attacks began, former Russian President Dmitry Medvedev, warned of retaliation against Ukraine if “terrorists of the Kyiv regime” were found to be behind them.
“If it is established that these are terrorists of the Kyiv regime, it is impossible to deal with them and their ideological inspirers differently,” he wrote in a post on Telegram.
“All of them must be found and mercilessly destroyed as terrorists. Including officials of the state that committed such atrocity. Death for death.”