In a telegram, Pope Francis on Saturday expressed his condolences over the murder of Ecuadorian presidential candidate Fernando Villavicencio.
Francis urged the political forces and citizens of Ecuador to unite "in a common effort for peace," according to Vatican News.
He condemned "the unjustifiable violence."
Villavicencio was shot dead Wednesday while leaving a campaign rally in the capital Quito.
The attack took place at 6.20 p.m. (2320GMT) as he was leaving the Anderson School.
Villavicencio, who most polls put in fourth place among the eight candidates competing in elections on Aug. 20, had built his campaign around the fight against corruption and organized crime.
