At least three people died and dozens were injured after Russia unleashed one of its fiercest aerial assaults on Ukraine since the full-scale invasion began more than three years ago, Ukrainian President Volodymyr Zelenskyy said Friday.

Zelenskyy called for stronger international pressure on Moscow following the overnight assault that struck “almost all” of Ukraine, affecting nine regions.

“Russia must be held accountable,” he wrote on X, urging Europe, the United States and other nations to “act decisively” to end the war.

He warned that those who fail to apply enough pressure are complicit in Moscow’s aggression.

Ukraine’s air force said Russia deployed 407 drones in a single night – the highest number since the invasion began in February 2022.

Zelenskyy also reported that more than 40 missiles and cruise missiles were fired.

The Ukrainian military said it intercepted 30 of 36 Kh-101 cruise missiles launched from Tu-95 and Tu-160 strategic bombers – the same Russian aircraft targeted by Ukrainian drones in a major June 1 strike.

Four of six Iskander-M ballistic missiles and two Iskander-K cruise missiles were also downed.

In total, Ukrainian forces said they shot down 199 combat drones and electronically disabled or forced down another 169 unarmed drones used as decoys to overwhelm air defenses. The previous record was 355 drones, detected May 26.

While the figures could not be independently verified, analysts say they reflect the scale of the attacks. Military experts believe nightly assaults involving 500 or more drones may soon become routine as Russia ramps up production.

The Russian Defense Ministry described the drone and missile assault as retaliation.

“The armed forces of the Russian Federation have delivered a massive blow in response to terrorist acts by the Kiev regime,” the ministry said.

It remained unclear whether the operation was Moscow’s anticipated response to recent Ukrainian strikes on Russian airfields that took out military aircraft.

Russian President Vladimir Putin has also recently accused Ukraine of “terrorism,” citing train crashes in Russia believed to have been caused by sabotage.

In Ukraine, air raid sirens sounded across all regions overnight.

Kyiv Mayor Vitali Klitschko said early Friday that at least four people were killed in the capital alone, with 20 injured. It was not immediately clear why his death toll differed from Zelenskyy’s, who said three people were killed in the country.

The Kyiv City Military Administration reported that drones struck multiple residential buildings and caused significant damage to a gas station in the city’s Dniprovskyi district.

In northwestern Ukraine, at least five people were injured in attacks on Lutsk. Mayor Ihor Polishchuk said 15 drones and six missiles hit the city, damaging an apartment building, vehicles, businesses and a government institution.

Ukraine has been defending itself against a full-scale Russian invasion since February 2022. Efforts to end the war through negotiations have so far made little progress, with both sides maintaining sharply divergent demands.