The US state department has warned tourists to “completely avoid” five states in Mexico because of rampant crime levels and gang activity.
Colima, Guerrero, Michoacán, Sinaloa and Tamaulipas have all been classified as a level-four risk, the highest in the scale.
That puts them at the same levels as conflict-ridden countries such as Afghanistan, Iraq and Syria.
Preliminary figures suggest that Mexico had a record number of murders in 2017.
Previously, the year with the most homicides had been 2011, when more than 27,000 people were killed according to official figures.
The state department is concerned about violent crime in all of the five states but also warns of specific dangers in each one of them.
A guide to Mexican drug cartels
In the case of Tamaulipas, it says that gun battles are widespread and warn of travel by both public and private bus as armed criminal groups take passengers hostage and demand ransom payments.
“Local law enforcement has limited capability to respond to violence in many parts of the state,” it says.
Sinaloa, where criminal gangs such as the Sinaloa cartel are active, is particularly dangerous.