Police in Fontana, California, discovered an underground shooting range while raiding a suspected gang hot spot, according to ABC News. “Last night members of the Fontana PD SMASH (Gang) Unit, served a search warrant on a residence of a known gang member. While searching the house a man hole was located that led to an underground hiding area and an additional underground area that was being used as a shooting range,” the department said on Facebook. “Numerous weapons were located, along with thousands of rounds of ammunition. Including a 100 round drum for an AR-15 rifle. All evidence was taken and suspects were booked without incident.” ABC notes that the department has not released information on the arrested or the charges they face. “We strongly recommend that you put as much effort as you did in your underground cave, into becoming a productive member of society. You will thank us later for this advice,” the Facebook post adds.