SAN DIEGO -- Three people were injured Friday afternoon in an explosion at a firing range in Escondido.
A SWAT team from the U.S. Department of Homeland Security was training at the Escondido Police Department's firing range when the small explosion occurred shortly before 4 p.m., according to Escondido police.
Two people were treated on scene and a third person was taken to a hospital to be treated for a leg injury.
Escondido police said none of their officers were involved in the incident.
It is not yet known what caused the explosion. The Department of Homeland Security will be conducting its own investigation.