THE left candidate for mayor of a violence-plagued Mexican city has been killed just as she began campaigning.

Two sources in the north-central state of Guanajuato said that Bertha Gaytan had been shot dead on Monday on a street in a town just outside the city of Celaya. 

Video footage of the scene posted on social media showed a small procession of people shouting “Morena!” — the name of Ms Gaytan’s party. At that moment, several shots are heard and people are seen running and falling down.