Ten people were shot dead at a bar in Monterrey, the capital of the northern Mexican state of Nuevo Leon, by gunmen who identified themselves as members of a drug cartel, an official said.
The gunmen arrived at the Matehuala bar in downtown Monterrey around 11 pm Monday and opened fire on the people inside, Nuevo Leon Security Council spokesman Jorge Domene said.
The gunmen told the bar's patrons and employees that they belonged to the Gulf cartel, one of Mexico's largest criminal organizations.
Four people were pronounced dead at the scene and four died while being treated at a hospital in Monterrey, Mexico's largest industrial city, Domene said.
Investigators later found the bodies of two more people in the bar's air ducts, where they had apparently tried to hide, Domene said.
Four of the victims worked at the Matehuala bar, Domene said.