ANKARA

Two workers are in critical condition after ordnance believed to date back to World War II exploded during construction work in Slovenia, local police said Friday.

In a statement, police said the explosion took place in the morning hours at a construction site in the Rozna Dolina area near the capital Ljubljana.

The two workers sustained serious injuries and were taken to the University Medical Centre Ljubljana, the statement said.

"The cause of the explosion remains unclear, but initial findings suggest that a small, unexploded World War II-era ordnance detonated during the construction activity," it added.

Police have cordoned off the area and launched an investigation into the incident.