“Poland strongly condemns the brutal attack at the Crocus City Hall in Moscow,” Tusk wrote on X, formerly Twitter, on Saturday evening.
“We all grieve for the families of the victims. We hope that this terrible tragedy will not become a pretext for anyone to escalate violence and aggression.”
Poland’s Defence Minister Władysław Kosiniak-Kamysz said all of the country’s security agencies were analysing and monitoring the situation, announcing a reinforcement of troops on the EU and NATO country’s eastern border in light of the attack.
Poland has been one of Ukraine’s most steadfast backers ever since the beginning of the all-out Russian invasion of the neighbouring country in February 2022.
Unidentified perpetrators fired indiscriminately at concert-goers at the Crocus City Hall venue in the outskirts of northwestern Moscow on Friday evening. Explosions were heard and a large blaze later led to the collapse of the building’s roof.
The death toll from the attack rose to at least 133 on Saturday, with emergency workers continuing to search for survivors among the rubble.
Islamic State has claimed responsibility for the attack, but Russian authorities have so far not commented on that, instead suggesting Ukraine might have been involved, accusations Kiev swiftly denied.