Recent violent attacks have prompted the U.S. Embassy to urge U.S. citizens to delay unnecessary travel to parts of Durango, Coahuila and Chihuahua states (see details below) and advise U.S. citizens residing or traveling in those areas to exercise extreme caution. Drug cartels and associated criminal elements have retaliated violently against individuals who speak out against them or whom they otherwise view as a threat to their organizations. These attacks include the abduction and murder of two resident U.S. citizens in Chihuahua.
...Criminals have followed and harassed U.S. citizens traveling in their vehicles in border areas including Nuevo Laredo, Matamoros, and Tijuana. Travelers on the highways between Monterrey and other parts of Mexico to the United States (notably through Nuevo Laredo and Matamoros) have been targeted for robbery and violence and have also inadvertently been caught in incidents of gunfire between criminals and Mexican law enforcement. Such incidents are more likely to occur at night but may occur at any time....During demonstrations or law enforcement operations, U.S. citizens are advised to remain in their homes or hotels, avoid large crowds, and avoid the downtown and surrounding areas. Since the timing and routes of scheduled marches and demonstrations are always subject to change, U.S. citizens should monitor local media sources for new developments and exercise extreme caution while within the vicinity of protests.
By the way, you cannot carry arms into Mexico except by special arrangement, only for hunting purposes. So fuggedabout, you know, self-defense.
Quoted by Ace for your safety and benefit.