The paper said the likely reason for the bombs falling short of their targets was faulty guidance systems. Russia’s glide bombs, which have been credited with being the power behind its recent advances, are Soviet-era heavy munitions retrofitted with guidance systems that experts say are unreliable.

Most of the bombs launched between April 2023 and April 2024 failed to detonate, The Washington Post reported, citing a document it said had been acquired by Ukrainian intelligence and was probably written by Russian local rescue services.

Many of the incidents mentioned in the document have been verified by independent Russian media service Astra, the paper wrote.

The daily said at least four of the faulty bombs hit Belgorod itself, a city of around 400,000 inhabitants about 30 kilometers from the Ukrainian border.

Another seven were found in the city’s suburbs, mostly by Russian civilians. One of the earliest ones struck a usually busy road and exploded, leaving a 20-meter crater, the report claimed, adding that there were no fatalities as the incident occurred at night.

A further 11 bombs reportedly landed around the small Russian border town of Grayvoron. The Washington Post said local authorities generally report only “accidents,” blame enemy fire from Ukrainian forces, or offer no comments at all.

The daily added that on May 4, after the period it had investigated, a bomb fell on Belgorod injuring seven people and damaging more than 30 buildings. Astra reported that the weapon was a half-tonne FAB-500 glide bomb.

On May 12, The Washington Post reported an exploding bomb destroyed several floors of a residential building in the city, killing 17 people, an event the Russian military attributed to a Ukrainian missile strike.

However, the Conflict Intelligence Team (CIT), an independent group of Russian investigative journalists, established that the cause of the explosion was either another misfired FAB-500 or a stray anti-aircraft missile fired by Russia.

Astra estimates that in the last four months, during which time there has been an increase in Russia’s use of glide bombs, the country’s forces have accidentally dropped at least 100 of the weapons on its own territory or in occupied Ukraine.

Russia’s glide bombs are Cold War remnants “adapted with cheap pop-out wings and navigation systems,” the Washington Post wrote.

These features enable them to be launched at targets from a distance of around 40 km, leaving the Su-34 and Su-35 jets that carry them beyond the range of Ukrainian air defenses. CIT estimates that between 4% and 6% of Russia’s vast stocks of the munitions are defective.