Kyiv came under a combined drone and missile attack early on May 24, Mayor Vitaliy Klitschko said, describing explosions in the Ukrainian capital and saying that air defenses had been activated.

The city and the region are under a combined enemy attack,"Klitschko saidon Telegram.

Timur Tkachenko, head of Kyivs military administration, said two fires had broken out in the city's Sviatoshinskiy district west of the city center. Drone fragments had hit the ground there and in three other districts.

Klitschko ordered emergency crews to head to the district. There were no reports of deaths or injuries.

The attack came hours after Russia and Ukraine launched the biggest prisoner swap since the start of Russia's full-scale invasion. The two sides exchanged hundreds of soldiers and civilians in a process that was set to continue over the weekend, officials in both countries said on May 23.

"We are bringing our people home," Ukrainian President Volodymyr Zelenskyysaid in a poston Telegram. "The first part of the agreement on the 1,000-for-1,000 exchange has been implemented."

An exchange of 1,000 people from each side would be the largest of several prisoner swaps since the start of the full-scale invasion.

Zelenskyy said 390 people from each side were exchanged and the swap was expected to continue on May 24-25. That number included 270 soldiers and 120 civilians, Russian and Ukrainian officials said.

Hours earlier, US President Donald Trump congratulated both sides, adding on his Truth Social platform: "This could lead to something big???" Previous exchanges have not led to tangible progress on ending the war.

A day earlier, Zelenskyy said the prisoner exchange agreement was perhaps the only real result of the 90-minute meeting between Ukrainian and Russian negotiators in Istanbul on May 16 -- the first direct peace talks between Ukrainian and Russian officials since shortly after Moscow launched its full-scale invasion of Ukraine in February 2022.

The exchange took place at Ukraine's border with Belarus, a Russian ally that has supported the invasion without sending its own troops to fight in the war.