SOFIA, : An accident at a military plant in southwest Bulgaria caused an explosion on Friday, injuring 10 people, authorities said. The defence ministry said the explosion was caused by workers mishandling ammunitions at the plant in the town of Kostenets, about 70 kilometres southeast of the capital Sofia. "Some 10 people were injured and hospitalised following the explosion," the health ministry said in a statement. "They're not seriously injured, they received cuts from broken glass." The interior ministry said in a statement that a signal about the explosion was filed at 0850 local time. The head of Bulgaria's fire safety and civil protection department, Nikolay Nikolov, said the situation was under control and that the town's nearly 10,000 residents were not in danger.