Ukraine has claimed responsibility for a missile attack on a temporary military barracks in the Russian-occupied Donetsk region after the Kremlin, in a rare battlefield admission, acknowledged that scores of its soldiers had been killed at a site in the city of Makiyivka.
"On December 31…in the settlement of Makiyivka, Donetsk region, up to 10 units of enemy military equipment of various types were destroyed and damaged," Ukraine's General Staff said on January 2 in a Facebook post.
"The losses of the occupiers' personnel are being clarified," it added.
The statement came shortly after the Russian military said 63 of its soldiers had been killed in a Ukrainian missile strike on temporary barracks near the Russian-occupied city of Donetsk after the Ukrainian Army and several posts by pro-Russian social media suggested hundreds had been killed.
The Russian Defense Ministry said on January 2 that "as a result of a strike on a temporary-deployment point by four missiles with a high-explosive warhead, 63 Russian servicemen were killed."
"All necessary assistance and support will be given to relatives and loved ones of the deceased servicemen," the ministry said.
Russia has rarely acknowledged casualties during its full-scale invasion of Ukraine, which began on February 24, 2022.
Hours earlier, the Ukrainian military, without initially acknowledging the attack itself, had suggested that hundreds of recently mobilized Russian troops died at a makeshift barracks in Makiyivka, a suburb about 15 kilometers outside of the occupied city of Donetsk in eastern Ukraine.
If such a scale of casualties is confirmed, it could represent one of the deadliest single incidents for the Russian side since the all-out invasion began 10 months ago and another potential rallying point for Ukraine and its international supporters in the conflict.
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RFE/RL is unable to corroborate battlefield accounts in areas of the heaviest fighting.
But expressions of shock and anger by Russians online about the incident and the apparent failure of the Russian military to guard an occupied vocational school where the purported recruits were gathered suggested that even normally pro-Kremlin Telegram groups were acknowledging a setback.
Some of the Russian groups suggested the shelling was the result of an attack by Ukraine with a high-precision HIMARS rocket.
The Strategic Communications Department of Ukraine's military said via Telegram on January 1 that an attack by "Santa" had resulted in "about 400 corpses" at an occupied vocational school called PTU-19 in the town of Makiyivka.
It said there were also 300 enemy troops wounded at Makiyivka.
It said the explosion was "a result of 'careless handling of heating devices,' neglecting security measures, and smoking in an unspecified place."
The Ukrainian side has routinely invoked such language after major events to suggest its defenders' responsibility without any outright claim.
The Russian Telegram channel Unofficial Beznosov 'Z' said the "strike was delivered at exactly 00:01 our time" on January 1 and expressed hope that Russian military commanders who decided to use the facility in question to gather troops "will be punished."
The Russian pro-military channel Tsargrad cited "hundreds" of dead, and the unofficial Operational Reports channel said 500 troops were dead. Others called the casualties suffered by the Russian side "substantial."