(Luis Sinco / Los Angeles…)
Although the number of U.S. citizens killed in Mexico this year is on the decline, the U.S. State Department has again issued a detailed travel warning for visitors to the country.
The state-by-state assessment urges travelers to "defer non-essential travel" to four of Mexico's 31 states, mostly in the country's northern regions. The agency also warns tourists to be cautious in several other cities and states.
In the state of Coahuila, for example, the travel warning noted that more than 100 prisoners escaped near the Texas border in September and have been involved in "a series of violent incidents since the escape."
The latest travel warning noted that 32 U.S. citizens have been murdered in Mexico in the first six months of 2012, compared with 113 in all of 2011.
In a statement, Mexican tourism officials said that protection of tourists is "at the pinnacle of importance to the Mexican government."
Quiz: How big a problem is texting while driving?
Criminal violence has been on the rise over the last six years since the outbreak of a drug war between the Mexican government and drug cartels.
The U.S. began issuing state-by-state assessments this year in response to criticism from Mexican tourism officials who said the warnings were too generalized.
For years, Mexico has been the top international destination for U.S. travelers. But the number of visitors from the U.S. to Mexico was flat in 2011 and declined slightly in the first eight months of 2012, according to federal statistics.
The latest travel warning urged U.S. travelers to be cautious even in popular tourist destinations, including the popular beach town of Mazatlan, in the state of Sinaloa. The State Department said travelers to Mazatlan "should exercise extreme caution particularly late at night and in the early morning."
How Mexico's drug war affects tourism
Mexico tourism grows thanks to non-U.S. visitors
Mexico aims to make end of Maya calendar a starter for tourism
Follow Hugo Martin on Twitter at @hugomartin