A powerful blast rocked a plant that produces optical equipment in Sergiev Posad, a city near Moscow, on Wednesday morning. The explosion injured 11 people and damaged several buildings in the vicinity, according to local authorities.

The explosion occurred around 9:30 a.m. local time at the Zagorsk Optical and Mechanical Plant (ZOMZ), a state-owned enterprise that is part of the Rostec corporation. The plant develops and manufactures optical and optoelectronic devices for military and civilian use.

According to a source from the emergency services, the blast was caused by a hangar with pyrotechnics that detonated on the premises. The source told TASS news agency that the explosion was heard in different parts of the city and shattered windows in several houses near the plant.

The Governor of the Moscow Region, Andrey Vorobyov, said he was heading to the scene of the incident and promised to provide assistance to the victims. He posted a message on his Telegram channel, saying: “I will be there in the near future.”

The head of the Sergiev Posad city district, Dmitry Akulov, also confirmed the explosion and said that representatives of law enforcement agencies were working at the site.