Ukraine’s capital Kyiv came under a large-scale Russian drone and missile attack overnight into Saturday, just hours after Russia and Ukraine began a major prisoner exchange.

Russia and Ukraine each exchanged 307 of their service personnel on Saturday on the second day of a prisoner exchange that, when completed, is set to be the largest such swap in the three-year war between the two countries.

The hourslong raids, involving hundreds of drones, were a reminder that any diplomatic resolution to the conflict remains far off.