Moscow said a Ukrainian air strike on army barracks in the Russian-occupied town of Makiivka killed 63 soldiers, in one of the bloodiest blows to the Kremlin’s ground forces since the start of the war.

The defence ministry said four high-explosive missiles struck the town’s temporary deployment base — a school building that stood near an ammunition dump and weapons cache. Two additional missiles were shot down by Russian air defences, it added, without saying when the attack occurred.

Russian military bloggers suggested casualties were far greater than the official figures, claiming that hundreds of newly mobilised troops had died or were missing. While not taking credit for the strike, the Ukrainian military said in a Telegram post that the Makiivka attack took place on New Year’s eve, killing 400 Russian soldiers and injuring 300.