A container at a military facility east of Tehran exploded on Thursday killing one soldier and injuring 10 firefighters, local media reported.

According to the reports, four firefighters were taken to the hospital and six others received treatment at the scene.

According to Iran’s semi-official Mehr news agency, the fire initially broke out within the container, followed by an explosion as firefighters attempted to get the blaze under control.

The reports did not state the cause of the fire and explosion.

A Tehran Fire Department spokesperson said the fire occurred at about 1:30 p.m. on Thursday and involved a 50-square-meter (538-square-feet) container.