An election official in Oaxaca, a party official in Guerrero and a campaign worker in San Luis Potosí were assassinated in the last two days.
A Oaxaca employee of the National Electoral Institute (INE) was gunned down and killed yesterday evening outside his home in Pinotepa Nacional.
Armed civilians fired several times at Joaquín Andrés Bernal, 52, according to early reports.
The murder came on the same day that two other electoral personnel in the Coast region city resigned their posts.
The president of the district council and its executive secretary both quit due to insecurity. Death threats had been made against them and their families.
In Guerrero, Jorge Luis Vargas of the Democratic Revolution Party was killed in gunfire at the campaign headquarters of the candidate for mayor of Chilapa.
Another incident occurred yesterday afternoon on the highway between Chilapa and Hueycantenango when six armed civilians intercepted a convoy accompanying the Institutional Revolutionary Party candidate for mayor of José Joaquín de Herrera.
Two municipal police officers were wounded.
In San Luis Potosí, a campaign worker for the candidate for mayor of Vanegas was murdered Wednesday night outside his home. Mateo Puente, 47, was working for the For Mexico in Front coalition candidate, Bertha Amaya.