NEW : roughly 25 families are expected to be affected by the decision . The travel warning was issued after an August 20 shooting in front of the American Foundation School in Monterrey , said the State Department . Diplomats are asked to have their children out of Mexico by August 20 . The travel warning follows an September 10 shooting in front of an international school . The U.S. has a travel warning issued for Monterrey because of drug-related violence .
NEW : roughly 25 families are expected to be affected by the decision . Diplomats are asked to have their children out of Mexico by August 20 . The travel warning follows an September 10 shooting in front of an international school . The U.S. has a travel warning issued for Monterrey because of drug-related violence .