An explosion took place at an industrial plant northeast of Moscow, injuring 22 people, Russian state-controlled media claimed, citing Russia's Emergency Situations Ministry.
According to Russian media, the explosion occurred at the Zagorsk Optical and Mechanical Plant, which develops and manufactures optical and optoelectrical devices for the military, law enforcement agencies, industries, and healthcare, in the town of Sergiev Posad.
Russian-state controlled news outlet TASS claimed the source of the explosion was caused by "human error" and originated in a pyrotechnics warehouse rented by a third company on the site of the plant.
The explosion comes after weeks of drone attacks on Russia, including Moscow.
Earlier on Aug. 9, Moscow Mayor Sergei Sobyanin claimed that Russian air defense successfully targeted and eliminated two drones near the city's periphery on the night of Aug. 9.
No information on specific drone types or the purpose of the drone attack was disclosed.