A Mexican drug gang spray-painted a pointed message for U.S. Drug Enforcement Administration agents next to a school: "Gringos (D.E.A.), We know where you are and we know who you are and where you go. We are going to chop your [expletive] heads"

The message was left in Chihuahua, which is only about 220 miles from the American border. The spray-painted message was discovered the same day that Mexican marines battled members of the Zeta drug cartel, leaving 15 cartel suspects dead and injuring six marines. The troops also detained 17 gunmen, according to a statement from the Mexican navy.