Eleven bodies were found over the weekend on a highway in the southern Mexican state of Guerrero, state prosecutors said.
The bodies, which were discovered early Sunday, showed signs of torture and had bullet wounds, the Guerrero Attorney General's Office said.
The victims - all males - were dumped at three different spots along the Siglo XXI highway, which links Guerrero to Michoacan state.
Messages signed by the Los Caballeros Templarios drug cartel were left with the bodies, suggesting that the killings were a settling of scores between rival drug gangs, media reports said.
The Caballeros Templarios cartel was founded in March 2011 by former members of the La Familia Michoacana organization and deals in both synthetic drugs and natural drugs.
The cartel has been fighting rival gangs for control of turf and smuggling routes in Guerrero and Michoacan states, both of which are located on the Pacific.
Los Caballeros Templarios is currently at war with the Jalisco Nueva Generacion, Los Zetas and Familia Michoacana cartels.
The violence has spiked this month in Mexico, with the Mexico City daily Reforma reporting recently that 231 people were murdered across the country from Aug. 4 to Aug. 10, raising the death toll for the year to 6,309.
More than 50,000 people, according to official figures, have died in drug-related violence in Mexico since late 2006, when President Felipe Calderon took office and declared war on the country's powerful drug cartels.
Calderon has deployed tens of thousands of soldiers and Federal Police officers across the country to combat drug cartels and other criminal organizations.
The use of the armed forces to fight drug traffickers, however, has failed to stem the violence.
Mexico registered 27,199 murders in 2011, or 24 per 100,000 people, the highest number since Calderon took office, the National Institute of Statistics and Geography, or INEGI, said in a report released on Aug. 20.
The Movement for Peace with Justice and Dignity, which was founded by human rights activist and poet Javier Sicilia, puts the death toll from Mexico's drug war at 70,000. EFE