The Ukrainian Army and a growing number of posts on pro-Russian social media have suggested that hundreds of recently mobilized Russian troops died in a New Year's attack on a makeshift barracks in a suburb 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.

RFE/RL is unable to corroborate battlefield accounts in areas of the heaviest fighting, and there was no confirmation from Russian officials of the alleged incident.

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.