BELGRADE, Serbia (AP) — A blast Tuesday at a Serbian factory that produces tires, protective gear and industrial explosives killed one person and injured four, police said.

The explosion occurred around 9a.m. at a fuel strip production unit of the Trayal Coorporation factory in the central city of Krusevac, according to a police statement.

It was not immediately clear what caused the blast, which also resulted in a fire at the complex. Police said the injured have been transferred to the Krusevac hospital.