Russia's sole optical fiber production plant, “Optical Fiber Systems” in Saransk city, has been out of operation since May 2025 due to a series of Ukrainian drone attacks, The Moscow Times wrote on February 26. They manufacture fiber optic cables that are used to control UAVs during military operations. Before the shutdown, the facility produced about 4 million. Fire in the main building of the Optical Fiber Systems company in Saransk.