Ukraine's Armed Forces hit a Russian military base in occupied Makiivka in Donetsk Oblast on New Year's night, killing 400 soldiers and injuring at least 300, the Strategic Communications Department of Ukraine's military wrote on Telegram.
Russian soldiers were stationed in a local school building, the report reads.
Ukraine's General staff hasn't reported this strike, only saying in its daily update that 760 Russian troops were killed on Dec. 31.
According to Russian Defense Ministry, cited by the Russian state-controlled news outlet RIA Novosti, Ukraine struck the military base in Makiivka using High-Mobility Rocket Artillery Systems (HIMARS). The ministry mentioned a far smaller number of casualties, namely 63 killed Russian servicemen.
One of the senior Moscow-installed proxies in Donetsk Oblast confirmed the Ukrainian attack, writing on Telegram that it happened just after midnight on Jan. 1. He didn't specify the number of casualties.
Russian war criminal and former top militant in Donetsk Oblast, Igor Girkin, also wrote about the alleged deadly strike, adding that the building in Makiivka and equipment nearby had been almost completely destroyed. Girkin added that the number of dead and wounded Russian conscripts "amounts to hundreds."
The Donbas region, made up of Ukraine's eastern Donetsk and Luhansk oblasts, is the scene of the war's most intense fighting as Russia seeks to capture the entire region.
Russia invaded and partially occupied the region in 2014, including Donetsk, the regional capital of Donetsk Oblast. Since the start of the full-scale invasion in February, Russia has occupied nearly all of Luhansk Oblast but has only managed to take parts of Donetsk Oblast.