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.

Officials say a massive Russian attack of drones and missiles targeted the Ukrainian capital and other regions early Sunday in the country for a second consecutive night, killing at least 12 people and injuring dozens.

The attack involved nearly 370 missiles and drones, according to Ukraine’s Air Force. At least 12 people were killed.