MOSCOW, June 20 (Xinhua) -- At least four people were killed and two others injured in an explosion and a subsequent fire at a gunpowder factory in southwestern Russia's Tambov region on Tuesday.
The blast occurred in the building of a gunpowder factory in the city of Kotovsk. The fire from the explosion has been extinguished, TASS news agency reported.
"Human error was the cause. I can say without any doubt that it was not a terrorist attack. Unfortunately, there were casualties," head of the Tambov region, Maxim Yegorov said, adding that nothing threatens the plant's workers or residents of neighboring settlements.
An investigation is underway. ■