The newly sworn-in mayor of a town in Mexico’s southern state of Oaxaca was on his way to his first official meeting at City Hall on Tuesday when he was killed by a group of gunmen, according to reports.

Alejandro Aparicio Santiago — a member of the National Regeneration Movement — had just taken office in Tlaxiaco when he was attacked.

Gov. Alejandro Murat promised a thorough investigation and said a suspect was already in custody. Four other people were wounded in the attack.

María Ascención Torres Cruz, another politician in the party of President Andrés Manuel López Obrador, was killed Sunday in the state of Morelos.

The state government announced the death on Twitter, writing, “Que en paz descanse” — Spanish for “Rest in peace,” according to NPR.

Holding public office can be very perilous in parts of the country. Between September 2017 and August 2018, 175 politicians were murdered, according to the consulting firm Etellekt.

Obrador, who campaigned on a platform of restoring order, formed a National Guard and has traveled with light security — riding in a Volkswagen with only unarmed citizens providing protection, NPR reported.

An analysis by the Economist magazine found that mayors in Mexico were often targeted after they cracked down on corruption and local crime, or because they sided with drug cartels at times and were pursued by their rivals.

In Oaxaca, where gangs are weak, mayors have been killed in disputes over land, according to the mag.