The explosion destroyed one of the buildings on the plant's territory, it said.
According to the broadcaster, the explosion was heard within a radius of many kilometers from the place of the explosion.
There is currently no information on casualties. Two people are being searched for at the scene.
Dozens of firefighters are on site, and air ambulance helicopters are also sent to the plant.
This is not the first explosion at KGHM's NitroErg factories. In January 2021, there was also an explosion in Beranka, in which one person died, another was injured.