At least five people have died in an explosion at a Mitsubishi Materials Corp chemicals plant in western Japan, national broadcaster NHK reported, citing local police.

"There was some explosion triggered by some sort of chemical reaction during plant operations," said a police spokesman in Mie, central Japan on Thursday. "It seems a number of people were killed or injured."

Ranko Hirai, a spokeswoman at Mitsubishi Materials, said: "We confirmed that there was an explosion at our plant in Yokkaichi, where we produce silicon materials. We have also confirmed that people were injured. We don't know about deaths."

An official at the local fire department said the fire has been distinguished.

Source: Agencies