A special police unit is working on the investigation after Mario Pineida was shot dead in Guayaquil, following reports that he and companions were ambushed as they left a butcher shop.Local media reported two people on a motorcycle opened fire, killing the 33-year-old Ecuadorian international who won the 2016 Ecuadorian championship with Barcelona SC and earned eight caps for Ecuador.The killing, treated as a possible contracted assassination, comes amid a surge in gang violence tied to Mexican and Colombian drug cartels that has made Guayaquil a focal point for criminal turf wars.