TEHRAN, Iran (AP) — An accidental explosion at a Revolutionary Guard ammunition depot west of Tehran killed at least 15 people on Saturday, officials said.

The explosions occurred when military personnel were transporting munitions at a base, said Guard spokesman Ramazan Sharif. The base is located outside Bidganeh village, 25 miles (40 kilometers) southwest of the capital.

The Guard is Iran’s most powerful military force.

“My colleagues at the Guard were transporting ammunition at one of the depots at the site when an explosion occurred as a result of an accident,” Sharif said.

At least 15 people were killed, state TV reported. The semi-official ISNA news agency said 10 people were injured and hospitalized. Sharif said some of those injured were in critical condition.