
The Avangard factory, located in the city of Sterlitamak, produces weapons and ammunition for Russia’s war in Ukraine, Russian media outlets reported.
Ukrainian drones targeting a major oil refinery hit the same region a month ago.
Bashkortostan’s head Radiy Khabirov said on Telegram on Saturday that “a pretty violent explosion destroyed one of the buildings” at the chemical factory site, killing three women.
He said another five people were wounded and hospitalized, two of them in serious condition.
The factory “carries out an important state-mandated mission” and “handles explosive materials,” Khabirov said.
He said the cause of the blast was being evaluated by experts.
Ukrainian drones on Sept. 18 hit a Bashkortostan oil refinery run by state-controlled giant Gazprom as part of a campaign targeting Russian energy revenues used to fund the military.
Khabirov at the time confirmed that two drones had hit the refinery.