Ukraine killed dozens of Russian servicemen using U.S.-supplied artillery to hit a base in an occupied part of the country on New Years Eve, Russia's Defense Ministry said on Monday.
Sixty-three servicemen died after 4 HIMARS artillery warheads struck a "provisional base," the Russian Defense Ministry said Monday in a Telegram post. Two projectiles were shot down, the statement added.
Earlier, a senior Russian-backed official in occupied Donetsk said "vocational school" in the city of Makiivka had been hit by U.S.-supplied HIMARS.
"A significant number of dead and wounded," Daniil Bezsonov said on Telegram Sunday night.
While Ukraine has not taken responsibility for the attack, its armed forces posted a cryptic message on Telegram: "As a result of 'careless handling of heating devices,' neglecting security measures, and smoking in an unspecified place, Santa packed about 400 corpses of Russian servicemen in bags."
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"About 300 more have wounds of varying degrees of severity," the account added.
NBC News was unable to verify claims from either side. Ukrainian officials were not immediately available for comment.
On Sunday, the leader of the self-proclaimed Donetsk People's Republic, Denis Pushilin, said many civilian facilities had come under Ukrainian fire over New Year's Eve, according to TASS.
Bezsonov criticized the "crowded deployment of personnel," which he said helped lead to the casualties.
Russian forces have also been pummeling cities across Ukraine in recent days, launching missile and drone attacks on key civilian infrastructure.
Overnight, capital Kyiv came under attack from the Iranian-made drones. Mayor Vitali Klitschko said 22 were destroyed over Kyiv, three in the outlying Kyiv region and 15 over neighboring provinces.
"As a result of the night shelling of the capital, energy infrastructure facilities were damaged. There are emergency power outages in the city," Klitschko said Sunday night in a Telegram post.
Energy infrastructure facilities were damaged as the result of the attack and an explosion occurred in one city district, the mayor said. It wasn't immediately clear whether that was caused by drones or other munitions. A wounded 19-year-old man was hospitalized, Klitschko added, and emergency power outages were underway in the capital.
Since October, Russia has carried out airstrikes on power and water supplies almost weekly.