KYIV (Reuters) - A Ukrainian military brigade said on Monday 19 of its soldiers were killed last week in a Russian air strike that President Volodymyr Zelenskiy described as "a tragedy that could have been avoided".
Ukrainian media reported that the soldiers were killed during an awards ceremony on Friday in the frontline Zaporizhzhia region of southeastern Ukraine.
A statement issued by the 128th Separate Mountain Assault Brigade on Monday provided the death toll but gave few other details.
Ukraine's defence minister said on Saturday an investigation had been launched into the attack, and Ukraine's military said separately that Russia had struck the Zaporizhzhia region with an Iskander ballistic missile.
Reuters has not been able to verify details of the attack independently. Russia's Defence Ministry said its forces had fired on Ukrainian troops in the region, and that it had killed up to 30 military personnel.
Ukraine's State Bureau of Investigations said on Monday it was investigating a decision by the military command to organise an event for Rocket and Artillery Day in a village close to the front line in Zaporizhzhia, but did not say what the event was.
"The main thing is to establish the complete truth about what happened and prevent such incidents happening again," Zelenskiy said on Sunday.
"Now the investigation must provide honest answers to the families of the fallen soldiers and society about how this tragedy occurred and whether any improper orders were issued."
Kyiv launched a counteroffensive in southeastern Ukraine in early June but progress has been slow against entrenched Russian forces who invaded Ukraine in February 2022.
(Reporting by Olena Harmash and Yuliia Dysa; Editing by Hugh Lawson and Timothy Heritage)