Russia's insisting it had no targets in a Ukrainian city where a rocket attack killed at least 52 civilians.
Hundreds more were also injured, after the strike on a railway station where people were waiting to escape the violence.
The Kremlin insists it doesn't use the type of weapon fired - although some experts dispute that.
Ukrainian President Volodymyr Zelenskyy wants to ensure justice is done:
"We are anticipating a solid global reaction to this war crime like mass killings in Bucha. Like many other Russian war crimes, the missile strike on Kramatorsk must become one of the charges at the tribunal - that will be for sure".
