The nighttime attack came after Russia and Ukraine completed the first phase of what is expected to be the biggest prisoner exchange since the start of the war. Over 600 Russian and Ukrainian servicemen were released Saturday as part of the second phase of the agreed prisoner exchange. Videos released by the Ukrainian Coordination Center for Treatment of Prisoners of War showed the hundreds of released men, most with shaved heads and draped in Ukrainian flags, hugging each other and calling their loved ones on the phone. Almost 800 people were released on Friday during the first phase of the swap.

Ukrainian President Volodymyr Zelenskyy and Russia’s defense ministry said each side brought home 307 more soldiers on Saturday, a day after each released a total of 390 combatants and civilians. “We expect more to come tomorrow,” Zelenskyy said on his official Telegram channel. Russia’s defense ministry also said it expected the exchange to be continued, though it did not give details. Hours earlier, explosions and anti-aircraft fire were heard throughout Kyiv as many sought shelter in subway stations as Russian drones and missiles targeted the Ukrainian capital overnight.

Russia launched dozens of attack drones and ballistic missiles at Kyiv overnight in one of the biggest combined aerial attacks on the Ukrainian capital of the three-year war, damaging several apartment buildings and injuring 15 people. Ukrainian president Volodymyr Zelensky said in a social media post it had been a “tough night” for Ukraine, and called for new international sanctions to pressure Moscow into agreeing to a ceasefire. The Kyiv city military administration and the police reported damage in six districts of the Ukrainian capital, and a total so far of 15 people wounded.