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

Hours earlier, the Ukrainian capital, Kyiv, and other regions came under a massive Russian drone-and-missile attack that killed at least 12 people and injured dozens. Ukrainian officials described it as the largest aerial assault since Russia’s full-scale invasion of Ukraine in February 2022.

Late Sunday, Ukrainian cities came under attack for a third straight night with Kyiv Mayor Vitali Klitschko reporting that air defense forces were working in the capital against enemy drones. Oleh Syniehubov, the head of the Kharkiv military administration, said Kharkiv and its suburbs were also under attack by drones.Information about victims was being clarified, Syniehubov said, urging residents to “stay safe places until the end of the alarm.”

Earlier, Russia’s Defense Ministry said each side exchanged 303 soldiers, following the release of 307 combatants and civilians each on Saturday, and 390 on Friday — the biggest total swap of the war.

Ukraine’s President Volodymyr Zelenskyy confirmed Sunday’s exchange, saying on X that “303 Ukrainian defenders are home.”

Nataliya Borovyk, the sister of released Ukrainian soldier Ihor Ulesov, was overwhelmed when she learned of her brother’s return.

“My uncle had to calm me down and put me in a taxi so I could get here,” she told the Associated Press. “A moment like that stays with you forever.”

In talks held in Istanbul earlier this month — the first time the two sides met face to face for peace talks — Kyiv and Moscow agreed to swap 1,000 prisoners of war and civilian detainees each. The exchange has been the only tangible outcome from the talks.

Largest aerial attack of the war

The scale of the onslaught was stunning — Russia hit Ukraine with 367 drones and missiles, the largest single aerial attack of the war, according to Yuriy Ihnat, a spokesperson for Ukraine’s Air Force.

In all, Russia used 69 missiles of various types and 298 drones, including Iranian-designed Shahed drones, he told the Associated Press.

For Kyiv, the day was particularly somber as the city observed Kyiv Day, a national holiday that falls on the last Sunday in May, commemorating its founding in the 5th century.

Zelenskyy said Russian missiles and drones hit more than 30 cities and villages, and urged Western partners to ramp up sanctions on Russia — a longstanding demand of the Ukrainian leader but one that despite warnings to Moscow by the United States and Europe has not materialized in ways to deter Russia.

“America’s silence, the silence of others in the world, only encourages” Russian President Vladimir Putin,” Zelenskyy wrote on X. “Without truly strong pressure on the Russian leadership, this brutality cannot be stopped. Sanctions will certainly help.”

U.S. President Donald Trump made it clear he is losing patience with Putin, leveling some of his sharpest criticism at him on Sunday night.

“I’ve always had a very good relationship with Vladimir Putin of Russia, but something has happened to him. He has gone absolutely CRAZY!” Trump wrote in a social media post. He said Putin is “needlessly killing a lot of people” by firing missiles and drones into Ukrainian cities “for no reason whatsoever.”

But Trump expressed frustration with Zelenskyy as well, saying that he is “doing his Country no favors by talking the way he does.”

Keith Kellogg, Washington’s special envoy to Ukraine, condemned the Russian attacks on X, calling it “a clear violation” of the Geneva Protocols. “These attacks are shameful. Stop the killing. Ceasefire now.”

Russia’s Defense Ministry, meanwhile, said its air defenses shot down 110 Ukrainian drones overnight.

No halt in fighting

The POW exchange was the latest of scores of swaps since the war began but also the biggest involving Ukrainian civilians.

Still, it has not halted the fighting. Battles have continued along the roughly 620-mile front line, where tens of thousands of soldiers have been killed, and neither country has relented in its deep strikes.

Russia’s Defense Ministry quoted Yaroslav Yakimkin of the “North” group of Russian forces as saying Sunday that Ukrainian troops have been pushed back from the border in the Kursk region, which Putin visited days ago.