Seven to nine concealed underground facilities are currently operating across Ukraine to assemble long-range drones, a representative of the pro-Russian underground told TASS.

The existence of such production sites had previously been reported by British broadcaster Sky News, whose journalists filmed a report inside one of the secret factories.

According to the TASS source, the exact locations of these facilities are kept under tight secrecy. Production can be moved elsewhere following strikes by the Russian Armed Forces or after information about a site appears in the media.

The underground representative said their information indicates that at least seven to nine such facilities are currently active across the country. The estimate applies only to sites assembling long-range unmanned aerial vehicles.

Locations are reportedly chosen in areas where industrial and engineering infrastructure dating back to the Soviet period remains available. The source named the Dnepropetrovsk Region, including the city of Dnepr, as well as the Vinnitsa and Khmelnitsky regions, areas near Lvov and Ivano-Frankovsk, and the Poltava Region.

FPV drone production follows a different model. According to the source, these drones continue to be assembled in private homes, apartments and basements in areas close to the front line. The large number of small production sites makes that network more complex and less transparent.