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 have exchanged hundreds more prisoners as part of a major swap after an overnight attack on the Ukrainian capital that injured at least 15.

Russia and Ukraine began their largest exchange of prisoners of war on Friday, with each side returning 390 soldiers and civilians, according to both governments. More swaps were expected on Saturday and Sunday, as the two countries have committed to exchange 1,000 prisoners each.