Another journalist has been gunned down in central Mexico. More than a dozen journalists have been killed in the country so far this year.

The wave of violence against journalists in Mexico continued this week with the murder of Ernesto Mendez, director of local news outlet “Tu Voz.”

Mendez and three others were murdered in San Luis de la Paz, Guanajuato, late Tuesday night, after a group of armed assailants broke into a bar owned by the journalist's family, according to press freedom organization Article 19.

The group said Mendez had previously received threats and has called on the Mexican government to take urgent action to investigate the case and to protect his colleagues and family.

At least 13 journalists have been murdered this year in Mexico. Article 19 says at least nine of those murders are suspected of being related to the person’s work.