Ukraine says mass grave found near recaptured city Izium

Ukrainian authorities found a mass grave of more than 440 bodies in the northeastern town of Izium that was recaptured from Russian forces days ago.

Thousands of Russian troops fled Izium last weekend after occupying the city and using it as a logistics hub in the Kharkiv region. They left behind large amounts of ammunition and equipment. 

"I can say it is one of the largest burial sites in a big town in liberated (areas)... 440 bodies were buried in one place," Serhiy Bolvinov, the chief police investigator for Kharkiv region, told Sky News. "Some died because of artillery fire ... some died because of air strikes."

Reuters could not immediately verify the Ukrainian claim and there was no immediate public comment from Russia on the allegation.

President Volodymyr Zelenskiy, who had paid a surprise visit to Izium on Wednesday to greet Ukrainian troops, put the blame on Russia and likened the discovery to what happened in Bucha, on the outskirts of the capital Kyiv in the early stages of the late February invasion by Russian forces.

Ukraine and its Western allies have accused Russian forces of perpetrating war crimes there. Tens of thousands of civilians were likely killed in a separate Russian assault on the southern port of Mariupol, Ukrainian officials said in April.

"Russia is leaving death behind it everywhere and must be held responsible," Zelenskiy said in a video address late on Thursday.

Russia has denied targeting civilians or committing war crimes.

FORTIFYING

After a week of rapid Ukrainian gains in the northeast, Ukrainian officials said Russian forces were fortifying defences and it would be hard to maintain the pace of the advance.

Russian President Vladimir Putin has yet to comment publicly on the setback suffered by his forces this month. Ukrainian officials say 9,000 sq km has been retaken, territory about the size of the island of Cyprus.

Footage shot by Reuters on Thursday in the eastern town of Kupiansk, which Ukrainian forces recaptured last week, showed many buildings had been damaged or burned out.

The speed of the advance has lifted hopes of further gains before the winter sets in.

But Serhiy Gaidai, governor of Ukraine's eastern Luhansk region, said it would still be a tough fight to wrest control of his region back from Russia, which recognises it as an independent state controlled by separatists.

There was no let-up either in Russia's daily missile strikes on Thursday, a day after it fired cruise missiles at a reservoir dam near Kryvyi Rih, Zelenskiy's hometown in central Ukraine.

Authorities in Kryvyi Rih are working to repair the damage and as a result water levels are receding, said Kyrylo Tymoshenko, deputy head of the presidential administration.

Ukrainian forces repelled three Russian attacks north of the city of Donetsk, the armed forces' general staff said in a Facebook post.

Russian forces had launched attacks on several settlements on the Kharkiv frontline in the past 24 hours, the General Staff of Ukraine's Armed Forces said.

Reuters was not able to verify battlefield reports.