Russia and Ukraine swapped hundreds more prisoners on Sunday, the third and last part of a major exchange that reflected a rare moment of cooperation in otherwise failed efforts to reach a ceasefire in the more than three years of war.

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

Russian forces launched 367 drones and missiles at Ukrainian cities overnight, including the capital Kyiv, in the largest aerial attack of the war.