Thirteen police officers were wounded in shootings over a 24-hour period across four states Friday.  Nine of the wounded were from one incident in Phoenix.

"This is what we call the war on cops," Betsy Brantner Smith, spokeswoman for the National Police Association and a 29-year police veteran who trains officers, told Fox News Digital

"[W]e are constantly attacked, and we are either attacked doing very simple things — traffic stop, responding to a 911 call, a domestic. All of that."

The incidents happened in Arizona, Maryland, New Mexico and Pennsylvania.