In this photo taken from video distributed by the Russian Defense Ministry Press Service on Monday, May 26, 2025, Russian serviceman train to operate military drones in an undisclosed location. (Russian Defense Ministry Press Service via AP)

KYIV, Ukraine (AP) — Russia overnight launched the biggest drone attack on Ukraine in the more than three-year war, a Ukrainian official said Monday. U.S. President Donald Trump said Russian leader Vladimir Putin has gone “crazy” by stepping up the bombing of Ukraine while the U.S. tries to broker peace.

The Russian bombardment on Sunday night included 355 drones, Yuriy Ihnat, head of the Ukrainian air force’s communications department, told The Associated Press.

Russia also fired nine cruise missiles during the attack, Ukrainian authorities said. Officials reported some civilians were injured. No deaths were immediately reported.

On Saturday night, the Ukrainian capital Kyiv and other regions came under a massive Russian combined drone-and-missile attack that killed at least 12 people and injured dozens. Ukrainian officials described that bombardment as Russia’s largest aerial assault during the conflict, using 69 missiles of various types and 298 drones.

The numbers could not be independently verified, and there was no immediate comment from Russian authorities.

The U.S., backed by European leaders, has pushed to stop the fighting, but without making a breakthrough. Efforts to broker a ceasefire and engage both sides in efforts to reach a peaceful settlement have shown few results.

Trump made it clear he is losing patience with Putin. “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 on Sunday night.

Trump said Putin is “needlessly killing a lot of people,” pointing out that “missiles and drones are being shot into Cities in Ukraine, for no reason whatsoever.”

The U.S. president warned that if Putin wants to conquer all of Ukraine, it will “lead to the downfall of Russia!” But Trump expressed frustration with Ukrainian President Volodymyr Zelenskyy as well, saying that he is “doing his Country no favors by talking the way he does.”

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

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.

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.