Ukrainian authorities found a mass grave containing 440 bodies in a northeastern city recaptured from Russian forces, calling it proof of war crimes carried out by the invaders in territory they had occupied for months.
"Russia is leaving death behind it everywhere and must be held responsible," Ukrainian President Volodymyr Zelenskyy said in a video address overnight.
The mass grave discovered in the former Russian front-line stronghold of Izium would be the biggest in Europe since the aftermath of the Balkan wars of the 1990s. Ukrainian forces retook Izium after thousands of Russian troops fled the area, abandoning weapons and ammunition.