A fire engulfed a multi-story office building in western Russia, killing eight, Monday, Russia’s state-owned news agency TASS reported.

The office building in Fryazino — about 16 miles northeast of Moscow — caught fire at about 2:39 p.m. Moscow Time (7:39 a.m. ET), according to TASS. The fire reportedly spread over about 5,000 square meters (over 53,800 square feet), engulfing the building’s top four floors and requiring over 130 firefighters and 50 vehicles, including helicopters.

“Two people died after jumping out of a window,” a spokesman for the local emergency service reportedly told TASS. “Six people stayed inside the building where interior structures collapsed. According to preliminary data, they died,” he reportedly said.

Only one of the nine persons in the building at the time of the fire was rescued, the spokesperson reportedly added.

“The extinguishing operation is complicated by the presence of gas-air mix canisters inside the building. The firefighters continue working to eliminate the fire,” the Russian Emergency Situations Ministry’s press office told TASS. (RELATED: Videos Show Aftermath Of Deadly Factory Explosion That Killed At Least 22)

A factory building is on fire in the Moscow Region. Thick smoke is billowing from the structure, a TASS correspondent reports.

Video: Sergey Savostyanov/TASS pic.twitter.com/qJmJCCrxGA

— TASS (@tassagency_en) June 24, 2024

Moscow region Governor Andrei Vorobyov identified the building as home to the Platan Research Institute, according to reports. Several Russian Telegram outlets also echoed the same, Newsweek reported. The institute manufactured electronic devices, The Kyiv Independent reported. The devices were used for military purposes and the institute has been under U.S. sanctions since Jun. 2022, four months after Russia’s illegal invasion of Ukraine, according to The Moscow Times.

“One of Russia’s main defense electronics producers and research centers, NII Platan near Moscow, is on fire, with staff trapped inside,” Yaroslav Trofimov, chief foreign affairs correspondent at the Wall Street Journal, posted on Twitter.

“According to Platan’s archived website, its components are used in all Russian fighter jets, nuclear launch munitions, S-400 air defenses and various guided munitions,” Trofimov added, sharing both a video of the incident and a screenshot of what appeared to be a document or webpage.

“The devices developed by the Platan Research Institute are still used in the most important systems of military, missile, aviation, instrument-making, and radio-electronic equipment,” a translation of the screenshot partly read.

“[…] 30 patents for inventions were received in the USA, Japan, Great Britain, France, Canada, Germany, Switzerland, the Netherlands and other countries of the world,” the translation also read.

Can the Putin no longer protect the Russian speakers of the Russian defense industry?

And what of the “ethnic Russians” of the Moscow region?? pic.twitter.com/3ISLeEVaYY

— Jay in Kyiv (@JayinKyiv) June 24, 2024

However, Russia‘s state-owned JSC Ruselectronics denied that the building belonged to the institute or that it was of any use to Russia’s defense industry, saying it was privatized in the 1990s, TASS reported.

An emergency official reportedly told TASS most of the office space in the building had been rented off and the fire could have started from there.

Nearby companies were carrying on as usual, TASS reported.

Russian authorities have launched a criminal investigation into the incident, according to TASS.