A gunfight between the Mexican army and members of a drug cartel left at least 12 people dead on Wednesday, according to officials cited by the BBC.
Among the dead were two soldiers.
A press officer from the state attorney general's office said, "Ten of the dead were civilians, apparently members of an armed group, and two were soldiers... who were on patrol," according to AFP.
The shoot out happened in Guasave, in the northwestern state of Sinaloa, which according to AFP is the cradle of Mexico's drug trafficking industry. The Sinaloa cartel is headed by Joaquin "El Chapo" Guzman, Mexico's most wanted fugitive.
More on GlobalPost: Sinaloa: Mexico arrests 2 nephews of cartel leader Ismael 'El Mayo' Zambada
According to the BBC, gunmen ambushed an army patrol using grenades and automatic weapons, before retreating to a hotel as reinforcements from the police and military closed in.
State governor Mario Lopez Valdez said, "An operation is under way to ensure that calm and security return to the Guasave area," according to the BBC.
The AFP reported that at least 22 others had been killed in similar clashes in the state since Saturday. School and businesses remained closed on Wednesday.
The prosecutor's office said that soldiers seized vehicles and weapons, including a Barrett rifle that can penetrate armored vehicles.
More on GlobalPost: Peru, Latin America's hidden growth story