Ukrainian drones struck deep inside Russia in an overnight attack targeting an oil facility serving a military airfield in the city of Engels, nearly 400 miles from the border, Ukraine’s military said Wednesday.

An overnight strike on Lyudinovo in Kaluga region ignited a key oil facility supplying the Putin war machine, then the Uzlovaya oil depot in Tula region went up in flames too

Ukraine launched its "most massive" attack against Russian military and industrial facilities in a range of up to 1,100 kilometers (620 miles) overnight on Jan. 14, the General Staff of Ukraine’s Armed Forces reported.

Ukraine launched waves of long-range strikes, including its ATACMS and Storm Shadow missiles, at targets inside Russia.

While air raid sirens during visits by foreign leaders have sounded before, it is rare for air defenses to actually have to fight off attacking drones.

The Russian Defense Ministry said that Ukraine launched six ATACMS missiles overnight at the Bryansk region, but that all of them were downed by air defenses. The ministry also said that 146 Ukrainian drones had been shot down outside the conflict zone over the last day.

Located in Saratov Oblast, over 750 kilometers from the Ukrainian border, Engels airbase is home to Russian heavy bombers.

Ukraine used six British Storm Shadow missiles and US-made Atacms tactical ballistic missiles in what Kyiv described as its “largest attack” on Russian military facilities.

Ukraine continues to cripple Russia's energy sector by hitting numerous oil refineries, depots, chemical plants, and more with drones.

Ukraine launches one of the largest missile and drone attacks of war into Russia - Moscow say Kyiv fired six US-made ATACMS ballistic missiles, six British Storm Shadow cruise missiles and at least 14

Europe warns its airlines to stay away through next summer, as Ukraine turns skies of western Russia into a battlefield.