Russia and Ukraine swapped hundreds more prisoners on Sunday, the Russian defense ministry said. The announcement came hours after a massive Russian drone-and-missile attack targeted Ukraine.

Ukraine and Russia, earlier this month, agreed to exchange 1,000 prisoners of war and civilian detainees each in a rare moment of cooperation in more than three years of war.

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