Russian nationalists and some lawmakers have demanded punishment for commanders they accused of ignoring dangers as anger grew over the killing of dozens of Russian soldiers in one of the Ukraine war's deadliest strikes.

In a rare disclosure, Russia's defence ministry said 63 soldiers were killed on New Year's Eve in a fiery blast that destroyed a temporary barracks in a vocational college in Makiivka, twin city of the Russian-occupied regional capital of Donetsk in eastern Ukraine.

Russian critics said the soldiers were being housed alongside an ammunition dump at the site, which the Russian defence ministry said was hit by four rockets fired from U.S.-made HIMARS launchers.