A high-tech factory in central Russia is creating deadly thermobaric drones that are highly destructive, an investigation has found.

They work by creating a vortex of high pressure and heat that can penetrate thick walls. They suck out all the oxygen in their path, and have a fearsome reputation because of the injuries inflicted even outside the initial blast site. These include collapsed lungs, crushed eyeballs and brain damage.

But the Russians have another secret weapon.

It involves launching a small number of highly destructive thermobaric drones surrounded by huge swarms of cheap foam decoys.

Russia came up with the plan in late 2022 and codenamed it Operation False Target.

Engineers are manufacturing hundreds of decoy drones that are designed to overwhelm Ukrainian defenses as they try to protect against the new weapon, AP's investigation found.

It is intended to force Ukraine to expend scarce resources to save lives and preserve critical infrastructure, including using expensive air defense munitions, according to a person familiar with Russia’s production and a Ukrainian source.

Rescue workers in Ukraine work on a home damaged by Russian drone strikes. - Reuters

Neither radar, sharpshooters nor even electronics experts can tell which drones are deadly in the skies.

The investigation reveals that unarmed decoys now make up more than half the drones targeting Ukraine and as much as 75 per cent of the new drones coming out of the factory in Russia’s Alabuga Special Economic Zone.

The information came from a person familiar with Russia’s production, who spoke on condition of anonymity because the industry is highly sensitive, and a Ukrainian electronics expert. The same factory produces the particularly deadly variant of the Shahed unmanned aircraft armed with thermobaric warheads, the person said.

In October, Moscow attacked with at least 1,889 drones – 80 per cent more than in August, according to an analysis that tracked the drones for months.

During the first weekend of November, the Kyiv region spent 20 hours under air alert, and the sound of buzzing drones mingled with the boom of air defenses and rifle shots.

This weekend, Russia launched 145 drones across Ukraine, just days after the re-election of Donald Trump threw into doubt US support for the country. Since summer, most drones crash, are shot down or are diverted by electronic jamming, according to an analysis of the Ukrainian military briefings.

Less than 6 per cent hit a discernible target, according to the data since the end of July.

But the sheer numbers mean a handful can slip through every day – and that is enough to be deadly.

Russia and Iran signed a $1.7 billion deal for the Shaheds in 2022, after President Vladimir Putin invaded neighbouring Ukraine, and Moscow began using Iranian imports of the unmanned aerial vehicles, or UAVs, in battle later that year. Soon after the deal was signed, production started in Alabuga.

Russian President Vladimir Putin has increased drone use in his nation's attacks against Ukraine. - AP

Serhii Beskrestnov is a Ukrainian electronics expert and more widely known as Flash. His black military van is kitted out with electronic jammers to down drones. He explained that the thermobarics were first used over the summer and estimated they now make up between 3 per cent and 5 per cent of all drones.

For Russia, the benefits are huge.

An unarmed drone costs considerably less than the estimated $50,000 for an armed Shahed drone and a tiny fraction of the cost of even a relatively inexpensive air defense missile. One decoy with a live-feed camera allows the aircraft to geolocate Ukraine’s air defenses and relay the information to Russia in the final moments of its mechanical life.

And the swarms have become a demoralising fact of life for Ukrainians.

Both Beskrestnov and the person familiar with Russian drone production said engineers at Alabuga are also constantly experimenting, putting Moscow at the cutting edge of drone production.

To make electronic interference harder, they add Ukrainian SIM cards, roaming SIMS, Starlinks, fiberoptics – and can sometimes receive real-time feedback before the drones are jammed, downed or run out of fuel.

Sometimes they attach a silver-painted foam ball to make the drone seem larger on a radar.