At a secret location in rural Ukraine, columns of attack drones are assembled at night and in near silence to strike deep inside Russia.

Their targets are strategic: oil refineries, fuel depots, and military logistics hubs. Since the summer, Ukraine’s long-range drone campaign has ramped up dramatically, pounding energy infrastructure across Russia and stretching Moscow’s air defenses thin.

Built from parts made in a scattered network of workshops, these drones now fly much further than at any point in the war.

Officers in body armor move with quick precision; headlamps glow red to stay hidden. Engines sputter like old motorcycles as exhaust fumes drift into the moonless night. Minutes later, one after another, the drones lift from a makeshift runway and head east.

The commander overseeing the operation — a broad-shouldered man identified only by his call sign, “Fidel,” in accordance with Ukrainian military regulations — watches through night-vision goggles as the drones climb into the star-filled sky.

He says that the drones have evolved and instead of flying 500 kilometers (310 miles) now some can strike targets in Russia within a 1,000-kilometer radius of the border.

“Effectiveness consists of three components. The first is hardware. This includes drones, technology, and everything else that goes with it. The second is planning. Specifically, the planning stage and analysis stage of the operation. And the third is people - most importantly those who manage resources and control this evolution that is taking place,” Fidel said.

The strikes have caused gasoline shortages in Russia, even forcing rationing in some regions and underscoring a growing vulnerability in the country’s infrastructure.

Western analysts say the attacks on energy infrastructure so far have had a serious — but not crippling — effect.

Ukrainian drones have repeatedly hit 16 major Russian refineries, representing about 38% of the country’s nominal refining capacity, according to a recent review by the Carnegie Endowment, a U.S.-based think tank.

But it argues the actual impact has been considerably more limited: most plants resumed operations within weeks, and Russia’s refining output has been cushioned by idle capacity and existing fuel surpluses.

The deep strikes have, however, given Kyiv the initiative at an important moment. The United States and Europe are ramping up sanctions on Russia’s oil industry even as Kyiv’s request for U.S. long-range Tomahawk missiles has stalled.

Much of Ukraine’s fleet is homegrown. The Liutyi, a workhorse of the nightly attacks, is a waist-high craft with a sausage-shaped body, a propeller at the back, and a distinctive triangular tail.

It looks neither sleek nor intimidating — more Home Depot than Lockheed Martin — but the ease of assembly means it can be kept hidden and constantly tweaked: optimized to slip through heavily monitored frontline airspace.

Typical of Ukraine’s no-frills war production philosophy, the Liutyi — whose name means “fierce” in Ukrainian — has become a symbol of national pride and recently featured on a local postage stamp.

The reach of these drones — with some models doubling in range over the past year to routinely strike targets within a 1,000-kilometer radius of the border — marks a shift in the geography of the conflict.

As both sides expand and develop their range of drone production, Fidel believes that it this will lead to an expansion of the “kill zone” – the area controlled by each side’s unmanned vehicles making it impossible for anything to work inside that area.

“The war will reach a point where there will be a 20-30 km kill zone. There will be certain approaches to this zone, and everything living on both sides will be destroyed in this zone by unmanned vehicles. And it will all come to the point where the price of passing through, in terms of human and technical losses, will be disproportionate to the distance that can be covered,” Fidel said.

AP video by Alex Babenko