Updated with new injury count.
A powerful explosion ripped through an optical equipment factory outside Moscow, triggering a “total evacuation” from all nearby buildings, local authorities said Wednesday.
At least 35 people were injured, with four in serious condition, authorities told state media.
Plumes of smoke billowed high into the air from the Zagorsk Optical-Mechanical Plant in the town of Sergiyev Posad, around 70 kilometers northeast of Moscow, according to video shared on social media.
Sergiyev Posad’s administration ordered a “total evacuation” of all plant buildings and workshops, according to its statement.
“There are a lot of buildings that had windows blown out,” it said on the messaging app Telegram.
The cause of the blast is believed to be “workflow violations” contrary to some reports of a possible drone strike, according to emergency services cited by RIA Novosti.
Russia’s Investigative Committee, which probes major crimes, said it has opened a criminal case on the “violation of industrial safety requirements for hazardous production facilities.”
The Zagorsk Optical-Mechanical Plant, referred to as “ZOMZ,” produces night vision devices and binoculars for the Russian military as part of Russia’s defense conglomerate Rostec.
The Moscow region’s prosecutor’s office later confirmed that an explosives warehouse located next to the plant was at the epicenter of Wednesday’s explosion.