Gunmen killed fifteen people on an isolated ranch in northern Mexico, including a prominent union leader, in the latest attack in an area overrun by drug gangs.
Margarito Montes, a well-known organiser of farm labourers, was among the bodies found riddled with bullets in trucks in the town of Hornos in southern Sonora yesterday, a state bordering the United States, a police spokesman said.
The killings had many of the hallmarks of hits by drug cartels, who 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.
Local farmers are often caught up in drug violence, paid or coerced to grow marijuana and opium poppies for powerful traffickers, often in northern states were cartels control large territories.