ALSO SEE: Three Killed, 49 Wounded in Intense Russian Air Attacks on Ukraine

The Russian attacks come after President Donald Trump likened the two sides to children on a playground who needed “to fight for a while.”

Moscow launched a major air assault across Ukraine overnight Friday in retaliation for Kyiv’s recent attacks, particularly its dramatic drone strike against the Russian bomber fleet.

Russia’s Defense Ministry said the strikes were in retaliation for the “terrorist acts” of the Ukrainian government, which is how it has been characterizing Ukraine’s assault over the weekend on Russian air bases as well as other attacks.

The overnight bombardment involved hundreds of drones and dozens of cruise and ballistic missiles, with the capital of Kyiv particularly hard-hit, killing at least three and injuring 20. Several regions in the far west of the country, normally untouched by strikes, were also targeted.

Russian President Vladimir Putin had told President Donald Trump in their recent phone call that he would be carrying out retaliatory strikes.

Despite sponsoring a peace process, Trump on Thursday appeared resigned to the two sides continuing fighting, comparing them in the Oval Office to children squabbling on a playground, adding, “you’re better off letting them fight for a while.”

Ukrainian officials said the assault damaged “civilian infrastructure,” but did not provide further details. However, power outages in Kyiv and the western city of Ternopil indicated that energy facilities were possibly a target. In its statement, the Russian Defense Ministry said the targets were military factories and warehouses.

Ukrainian President Volodymyr Zelensky said that the strikes involved “more than 400 drones and more than 40 missiles,” including ballistic missiles, and targeted nine Ukrainian regions across the country.

“Russia is not changing its handwriting,” he wrote in a post on Telegram, which included photos of bodies lying on the street and damage from the strikes. “Russia must answer for this … now is the moment when America, Europe and everyone in the world together can stop this war by putting pressure on Russia.”

Sunday’s drone attack targeted Russia’s strategic bomber fleet that Kyiv said has long been used to bomb Ukraine. On Friday, the Ukrainian air force said Tu-95 bombers — one of the types of planes targeted in the drone strike — had launched cruise missiles in the overnight assault.

The Ukrainian air force said air defenses shot down 32 of 38 cruise missiles and 368 of 407 drones as well as all six ballistic missiles. Ukraine has repeatedly asked for beefed air defenses from its Western backers.

Russia also reported it was attacked by Ukrainian drones, including on a factory in the Tambov region south of Moscow, the Engels air force base in the nearby Saratov region, and the airport at Bryansk near the Ukrainian border. Russia’s Defense Ministry said it destroyed 174 Ukrainian drones as well as Neptune missiles over the Black Sea.

Videos posted on social media showed huge billows of black smoke pouring into the sky at the site of Russia’s Engels air force base, which had previously been targeted by Ukrainian drones in January. Russian authorities confirmed there was a fire at an industrial enterprise at the site.

Kyiv appeared to bear the brunt of the Russian assault overnight, with ballistic missiles and waves of self-detonating drones killing three and injuring at least 20, according to the State Emergency Service. Kyiv’s mayor, Vitali Klitschko, had originally put the toll at four.

Vyacheslav Nehoda, head of the Ternopil Regional Military Administration in western Ukraine, wrote on social media that the attack was the largest on the region since the war began, and there were “multiple hits.”

The western Ukrainian city of Lutsk also came under attack, local officials said. One person was killed — a boy whose body was recovered from the rubble of a high rise building — and 27 were injured, Ukraine’s State Emergency Service said.

The assault was in retaliation for Ukraine’s extensive attack on Russia’s bomber fleet on Sunday, targeting air bases across Russia and damaging many nuclear-capable aircraft. Ukrainians celebrated the boldness of the operation — named “Spiderweb” by officials — but also braced themselves for the expected retaliation.

On Wednesday, Trump wrote on social media that Putin told him in a phone call earlier that day that he would respond to the attacks “very strongly.” Putin also told a meeting of his cabinet that the Kyiv government was run by “terrorists,” and rejected direct talks with Zelensky.

Trump’s comments were interpreted by observers in Russia as tacit agreement that Russia had a right to strike back at Ukraine. However, on Thursday Trump said that he told Putin to refrain from retaliating.

“I said, ‘Don’t do it. You shouldn’t do it. You should stop it,’” Trump said. “But again, there’s a lot of hatred.”

Trump officials have warned that the Ukrainian drone operation could be escalatory. Lt. Gen. Keith Kellogg, Trump’s envoy to Ukraine said on Tuesday that “the risk levels are going way up,” since Kyiv forces targeted Russia’s nuclear strike capability.

His daughter, Meaghan Mobbs, president of the Weatherman Foundation, tweeted to her father during the strikes suggesting that Russia was not interested in peace.

“Loud night in Kyiv, Dad! It might be the explosions and gunfire in the dead of night, but I get the strange feeling the Russians don’t want peace.”