Russian missiles struck Vinnytsia in central Ukraine Thursday, killing at least 20 people including three children, in what President Volodymyr Zelensky called "an open act of terrorism," reported AFP.

The midday attack on the city hundreds of kilometers from the frontlines and Russian troops came as EU officials convened in The Hague to discuss war crimes in Ukraine.

The charred remains of upturned cars surrounded by burnt debris were seen in images distributed by officials next to a business gutted by a fire with brown smoke billowing nearby.

"There were eight rockets, two of which hit the center of the city. Twenty people have died, including three children. There a large, large number of wounded," Zelensky said during an address European official at The Hague.

The Ukrainian leader led a moment of silence before urging European and International Criminal Court officials during an address to open a "special tribunal" into Russia's military operation.

"I believe it is inevitable that International Criminal Court will bring accountability to those guilty of crimes under its jurisdiction: war crimes, crimes against humanity, genocide."