Russia launched its largest aerial assault of its three-year war on Ukraine overnight, targeting the capital and other regions with missiles and drones for a second night in a row, even as the two sides prepared to conclude a major prisoner exchange.

Russia and Ukraine have swapped hundreds more prisoners of war, the third and last part of a major swap, hours after a massive attack by Moscow, killing at least 12.

Fourteen people were reported killed in Ukraine, with its air force saying 22 locations were hit by Russian air strikes.