The blast in the port city of Rostov-on-Don, near Russia’s border with Ukraine, early on Sunday morning woke residents, with clips showing seemingly hundreds of fireworks exploding at random.
More than 400 firefighters were brought in to deal with the blaze along with fire engines and search and rescue equipment.
Officials described it as a “large” fire that had affected 4,000 square metres of land and property and said the size and complexity of the blaze meant it had been assigned the “highest difficulty grade” by emergency crews.
There was no information immediately available about possible victims and the cause of the fire is still being investigated.
There have been numerous fires at firework factories around the world in recent years, including a blaze in Indonesia in 2017 that left 30 dead.