Military personnel check an armored U.S. Embassy vehicle after it was attacked by unknown assailants on the highway to Cuernavaca, Mexico, on Friday, Aug. 24, 2012, near Tres Marias. (AP Photo/Alexandre Meneghini)

Photo by: Alexandre Meneghini

Military personnel check an armored U.S. Embassy vehicle after it was attacked by unknown assailants on the highway to Cuernavaca, Mexico, on Friday, Aug. 24, 2012, near Tres Marias. (AP Photo/Alexandre Meneghini)