Moscow has charged 92 members of the Ukrainian armed forces with crimes against humanity.

Ukraine is also conducting its own war-crimes investigations, examining more than 21,000 war crimes and crimes of aggression allegedly committed by Russian forces since the start of the invasion on 24 February.

The head of Russia's investigative committee Alexander Bastrykin said that over 1,300 criminal investigations had begun into crimes against the peace and security of humanity.

Bastrykin proposed an international tribunal backed by countries that include Russian allies Iran, Syria and Bolivia.

Some 96 people, including 51 armed-forces commanders, are also wanted, Mr Bastrykin said.

However, the BBC said it has been unable to verify the claims.

'Crime scene'

The International Criminal Court (ICC), which has described Ukraine as a "crime scene", has also sent a team of investigators and forensics experts to Ukraine.

The Kremlin denies all war crimes, or that it has been targeting civilians.

It has regularly blamed Ukraine for shelling its own infrastructure and killing its own civilians, though these allegations have been widely dismissed by international leaders.