Ten suspected drug traffickers died in a shootout in the northwestern Mexican state of Sinaloa, officials indicated Thursday.
The 10 men, aged between 26 and 46, were shot dead late Wednesday after meeting with other criminals under a bridge.
"It seems that there was a disagreement that set off the shooting," the prosecutor's office added in a statement.
Police found nine AK-47 rifles and 229 AK-47 and 9mm bullet cases at the site, and were looking for a couple seen nearby.
A drug-producing state, Sinaloa is also the bastion of one of Mexico's most famous drug traffickers, fugitive Joaquin "El Chapo" Guzman.
Violence has escalated across Mexico this year in a drug war involving gangs and the authorities amid a government crackdown launched almost two years ago that has seen some 36,000 soldiers deployed across the country.
Mexico's top prosecutor said Monday that 5,376 drug gang-related killings have taken place so far in 2008, double the number during the same period last year.