MOSCOW - Alexander Bortnikov, director of Russia's Federal Security Service, said on Friday that Ukrainian military intelligence is directly involved in the terrorist attack at Crocus City Hall in the Moscow suburb.

A shooting at Moscow's Crocus City Hall concert venue on March 22, followed by a massive fire, resulted in at least 144 deaths and 551 injuries, according to official statistics

Bortnikov made the statement at a meeting of the Council of Heads of Security Agencies and Special Services of the Commonwealth of Independent States in Bishkek, Kyrgyzstan.

He said: "The investigation is ongoing, but it is already safe to say that Ukrainian military intelligence has a direct connection to this attack."

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Bortnikov promised that "all circumstances of the crime will be established, and everyone involved in it will not escape punishment."

A shooting at Moscow's Crocus City Hall concert venue on March 22, followed by a massive fire, resulted in at least 144 deaths and 551 injuries, according to official statistics.