KYIV, Ukraine — Russia and Ukraine engaged in large-scale dueling air assaults overnight Saturday, launching hundreds of drones in hourslong raids. The attacks came as both sides were carrying out the war’s largest prisoner exchange — a stark reminder that despite ongoing efforts to deescalate the conflict, a resolution remains far off.

Russia’s attack on Ukraine was particularly significant, involving 250 long-range drones and 14 ballistic missiles, with Kyiv, the Ukrainian capital, the main target. Ukraine’s air force said it had intercepted six missiles and nearly all the drones, but at least 15 people in Kyiv were injured as drones and debris from intercepted weapons crashed into apartments, setting them ablaze.

Kyiv residents were jolted awake by the booms of the city’s antiaircraft batteries trying to down incoming missiles and drones. The night sky lit up with bright streaks from climbing air defense missiles and red tracer trails from heavy machine guns. Explosions set off car alarms, adding to the cacophony of gunfire and the buzz of attack drones.

“It was a difficult night for all of Ukraine,” President Volodymyr Zelenskyy said in a statement Saturday morning. “With each such attack, the world becomes more certain that the cause of prolonging the war lies in Moscow,” he added, noting that Russia had repeatedly ignored Ukraine’s offers to enforce a temporary ceasefire.

Posting on X, U.K. Foreign Secretary David Lammy spoke of “another night of terror for Ukrainian civilians.”

Still, Ukraine has also escalated its air assaults on Russia in recent weeks, with Moscow a prime target. Just a few days ago, Ukraine fired hundreds of drones at Russia, the Russian Defense Ministry said, in one of the largest barrages of the war.

The strikes have caused major disruptions inside Russia, forcing temporary airport closures and bringing the war home in ways rarely seen.

Together, the attacks signal an escalating cycle of air assaults. Both sides have ramped up drone production and can now launch hundreds in a single night — a feat unimaginable in the war’s first year. They also are continuously enhancing drone capabilities, boosting their range and explosive payloads.

On Friday, a first group of 270 soldiers and 120 civilians from each side were exchanged, with many Ukrainian families traveling to northeastern Ukraine hoping to reunite with loved ones.

Another swap followed Saturday, involving 307 soldiers from each side.

“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.

In talks held in Istanbul earlier this month — the first time the two sides met face to face for peace talks since Russia’s 2022 full-scale invasion — Kyiv and Moscow agreed to swap 1,000 prisoners of war and civilian detainees each.

In a post on social media Friday announcing the swap, President Donald Trump asked, “This could lead to something big???”

But Saturday’s attacks underscored that for all the efforts toward deescalation, the fighting remains as fierce as ever.

On Friday, Russian Foreign Minister Sergey Lavrov said that once the prisoner exchange was completed, Moscow would present Kyiv with a draft document outlining its conditions for a peace agreement.

But few in Kyiv believe Russia is serious about ending the war. Russian forces have resumed offensive operations in eastern Ukraine, pushing across a key highway linking Ukrainian-held cities that anchor the area’s defenses. And during last week’s talks in Turkey, Russia insisted that any ceasefire must begin with Ukraine withdrawing from territory it still holds — a nonstarter for Kyiv.

Associated Press contributed.