Gunmen killed fifteen people on an isolated ranch in northern Mexico, including a prominent farmworker leader, in the latest grisly attack in an area overrun by drug gangs, local police said. Margarito Montes, a well-known organizer of agricultural laborers, was among the bodies found riddled with bullets in trucks in the town of Hornos in southern Sonora, a state bordering the US. The cause of the crime was unknown but the killings had many of the hallmarks of hits by drug cartels, which often use automatic weapons to murder people in groups to send a message to rivals. More than 15,000 people have been killed in drug-related violence in Mexico since President Felipe Calderon launched an army-led assault on cartels soon after taking office in 2006. (Reuters)
