June 1 (UPI) — Ukrainian intelligence officials claimed Sunday to have attacked at least 40 bombers deep inside Russia, which would be the most aggressive such attack on Russian territory since Moscow-led troops invaded Ukraine in 2022.

Ukraine targeted “41 strategic Russian aircraft” in an offensive code-named “Spiderweb,” NBC News reported, citing a source within the Security Service of Ukraine.

The attack happened at the Belaya air base in Russia’s Irkutsk region in Siberia, almost 3,000 miles from Ukraine, according to video posted by the Kyiv Independent.

Ukrainian President Volodymyr Zelensky said Sunday on X that he is “doing everything to protect our independence, our state, our people,” and said he was receiving regular updates from his security forces.

Andriy Yermak, head of the office of the President of Ukraine, posted an emoji on the spiderweb.

“At the right moment, the roofs of the cabins were opened remotely, and the drones flew to hit Russian bombers,” the Independent reported of the “Spiderweb” operation, which sources told the paper was a year-and-a-half in the making.

Ukraine announced in March that it had developed a new, more cost-effective drone with a range of nearly 2,000 miles, but did not say when they would go into operation or if these drones were used in the Sunday attack.

At least seven people died and more were injured when a passenger train derailed following a bridge collapse and explosion in Russia’s Bryansk region near Ukraine, Duetsche Welle reported. A second bridge was said to have collapsed in the Kursk region.

The Russian defense ministry said Ukraine lost 510 troops and five armored personnel carriers, although it offered no evidence in a post on Telegram.

Ukraine has not commented on the collapsed bridges or ensuing explosion and deaths.