A former governor of the Mexican state of Jalisco, Aristoteles Sandoval, was shot dead in the back in the bathroom of a restaurant in the popular beach getaway of Puerto Vallarta, according to local authorities.
The death of Mr Sandoval was announced by his successor as governor, Enrique Alfaro, while the Jalisco state attorney general, Gerardo Octavio Solis, gave details of where and how he was killed in a short video posted on social media.
Mr Sandoval's 2013-18 term as governor was overshadowed by the brutal rise of the Jalisco New Generation Cartel (CJNG), a local outfit which went from relative obscurity to become one of the most powerful drug gangs in the country.
Mexican President Andres Manuel Lopez Obrador offered his condolences and vowed to bring the perpetrators to justice.
"It is a matter that will be investigated so that the motive is known and those responsible are punished," said Mr Lopez Obrador during a regular morning news conference.
In the video, Solis said authorities were investigating the death and did not give an indication of who was responsible, beyond noting that the attacker appeared to be male.
Mexico has suffered record homicide levels under Mr Lopez Obrador, in part owing to turf wars involving the CJNG.
