Russia accidentally dropped at least 38 unguided bombs over its own territory in April 2023-April 2024, The Washington Post reported Monday, citing internal bomb cleanup and evacuation documents it obtained from Ukrainian intelligence.

The FAB-500 glide bombs that carry a 500-kilogram payload have fallen on Russia’s Belgorod region which borders Ukraine, the newspaper reported. Russia had started deploying modified Soviet-era FAB-500s with an attached wing and navigation kit earlier in 2023 as an alternative to dwindling precision-guided missiles.

Military expert Ruslan Leviev said that although the glide bombs’ retrofitted guidance systems are unreliable, “only a fraction of these bombs fail, so it doesn’t affect the practical effectiveness of this weapon, no matter how cynical that may sound.”