Mexico says it captured the leader of the brutal Zetas drug cartel, marking the biggest victory for its president in his fight against gang violence.

Scores of journalists have died in a country gripped by violence that has claimed an estimated 60 000 lives since 2006.

Mexico says its navy has captured one of the country’s most wanted drug bosses – the head of the Gulf cartel, Jorge Costilla, alias "El Coss".

Guatemala declared a 30-day state of emergency for the northern Peten region following a brutal weekend massacre of 27 people at a cattle ranch.

At least 11 bodies were found in five new mass graves located in Sinaloa state in north-western Mexico, state prosecutors said on Tuesday.

Mexican drug gangs branching out into new criminal activity are earning a steady stream of cash from the mass kidnapping of migrants.