Ukraine launched its heaviest drone attack on Russian territory since the war began, with hundreds of drones exploding across the Russian heartland and occupied territory.

At least 660 Ukrainian drones were downed by Russian defenses Thursday night into Friday, Russia’s Defense Ministry reported, though it remains unclear how many were actually fired.

Ukraine’s previous record involved 556 drones on May 17.

At least 12 regions were targeted in the attack, including Moscow and the surrounding area, St. Petersburg, Crimea and Russian-occupied territory on the war’s eastern front.

A hydroelectric plant and a chemical plant were reportedly damaged in the Tula region south of Moscow – with the chemical plant being a key piece of Russia’s explosives infrastructure, Ukrainian President Volodymyr Zelensky previously said.

At least two military vessels were also hit in Crimea – which Russia has held since 2014 – along with a series of air defense systems in Crimea’s eastern Kerch region, according to CBS News.

The full extent of the wider attack’s damage remains unclear, however, as Russia typically conceals information about the reality of Ukraine’s successes.

But the attacks followed Zelensky’s promise earlier this week to launch “a 40-day influence operation” with the goal of “compelling [Russia] to end the war.”

That vow was accompanied by days of other Ukrainian attacks which caused significant damage to Russia’s war infrastructure.

A series of satellite communications systems near Moscow were damaged Sunday, while fuel and power supplies were attacked in Crimea, Al Jazeera reported.

Several electrical plants were also damaged across Crimea on Wednesday.

A state of emergency was declared by Russian leaders in Crimea over the attacks – with Russian-installed governor Sergey Aksyonov acknowledging his defense capabilities were limited.

“There are no air defence systems in the world that are absolutely perfect in terms of security and effectiveness,” Aksyonov said in a social media post.

But Russia’s assault on Ukraine also continued.

At least two civilians were killed and seven injured by Russian strikes on Kharkiv Thursday after Russia launched a barrage of drones and guided bombs on 16 towns.

Ukrainian defenses managed to stop 174 out of 186 Russian drones launched in the attack.

Other barrages hit the capital region in Kyiv, with electrical systems, houses and civilian buildings also struck.

Despite Ukraine’s successes, the back and forth highlighted the state of near-stalemate the more than four-year war has settled into.

Zelensky expressed optimism this week about promises of support he got at the June G7 summit, while a NATO summit in July could also yield further support for Ukraine from western powers.

But rumors have also swirled that Russia is pressuring Belarus to allow its Ukraine-bordering territory to be used to open more fronts in the war.

Belarus has denied the claims.

With Post wires