Map of the U.S.-Mexico border region highlighting the Mexican state of Sonora in orange. A marker identifies Nogales, Sonora, where the U.S. Embassy issued a security alert on September 5 and restricted U.S. government personnel to essential daytime movement because of threat information. A second marker identifies Mexicali, Baja California, where a separate security alert was issued on August 24. A tooltip notes that Sonora is designated a U.S. State Department Level 3 travel advisory area, meaning Americans are advised to reconsider travel.