Mexico is no stranger to the assassinations of elected officials and candidates for office. And on Tuesday, the latest act of political violence to rock the nation occurred in a town in the southern state of Oaxaca, when the newly sworn in mayor was murdered by a group of gunmen while on his way to his first official meeting.

Alejandro Aparicio Santiago, a member of AMLO's National Regeneration Movement, had only just taken office in the town of Tlaxiaco when he was gunned down, according to the New York Post.

Holding elected office in Mexico is a perilous task. According to one figure, 175 politicians were murdered between September 2017 and August 2018. Aparicio Santiago wasn't the only NRM member to be murdered over the past week: On Sunday, María Ascención Torres Cruz was murdered in the state of Morelos.

Though AMLO campaigned on ending Mexico's violent war on the drug cartels, and travels around the country in a car with only light security, local politicians are often targeted because they cracked down on corruption and local crime, or because they cut a deal with one cartel and were targeted by that cartel's enemies. In Oaxaca, mayors have been killed in disputes over land.

Oaxaca Gov. Alejandro Murat promised a thorough investigation of the attack, which left four others injured.