Updated with new casualty counts and the number of dead and missing.

A powerful explosion occurred at an optical equipment factory outside Moscow, prompting a “complete evacuation” of all nearby buildings, and local authorities He said Wednesday.

Plumes of smoke rose high into the air from the Zagorsk Opto-Mechanical Plant in the town of Sergiev Posad, about 70 kilometers northeast of Moscow, as shown in multiple videos shared on social media.

At least 30 people have been hospitalized with injuries, six of them are in intensive care, Moscow Region Governor Andrei Vorobyov He saidAdding that another 26 people sought medical attention but did not require hospitalization.

State media reported that 56 people had sought medical attention as of Wednesday evening.

One of the victims died of his injuries, the state-run Tass news agency reported mentioned.

The Moscow region branch of Russia’s Ministry of Emergency Situations told Interfax on Thursday that 12 people remained missing for 24 hours after the deadly blast.

The Sergiev Posad administration ordered the “complete evacuation” of all factory premises and workshops, according to its statement.

“There are a lot of buildings that have had their windows blown out,” she said on messaging app Telegram.

It is believed that the explosion was caused by “workflow violations” in contrast to some reports of a possible drone strike, according To the emergency services cited by RIA Novosti.

The Russian Investigative Committee that investigates major crimes, He said A criminal case has been opened on “violation of industrial safety requirements for hazardous production facilities.”

Zagorsk Optical-Mechanical Plant, referred to as “ZOMZ” Produces Night vision devices and periscopes for the Russian army as part of the Russian defense conglomerate Rostec.

The Prosecutor’s Office of the Moscow Region later Certain An explosives depot located next to the factory was at the epicenter of Wednesday’s blast.

Governmental media selected The warehouse is identified as belonging to the pyrotechnics supplier “Piro Ross”, which has received numerous warnings of safety breaches in recent years and has been subject to bankruptcy action since April.

Peruvian director Sergey Chankayev to reject The official version is that the explosion occurred in his warehouse, claiming that the epicenter was adjacent to the storage of metal pipes.