Ukrainian President Volodymyr Zelensky said safety rules had been “violated,” leaving soldiers and civilians exposed to a deadly Russian missile strike on a village in the Zaporizhzhia region, which he described as “a tragedy that could have been avoided.”

A Ukrainian military brigade said Monday that 19 of its soldiers had been killed last week in an air strike during an award ceremony near the frontlines in Zaporizhzhia.

“The whole situation is being analyzed minute by minute,” Zelensky said Monday in an address to the nation. “It will be found out who exactly violated the rules on the safety of people in the area accessible to enemy aerial reconnaissance. There will be no avoidance of responsibility.”

Ukrainian Defense Minister Rustem Umerov on Sunday ordered a criminal investigation into the attack. “We must make every effort to protect our people and give honest answers to the relatives and friends of the fallen soldiers,” Umerov said in a statement on Facebook.