Mexican authorities say gunmen killed a traffic police officer as he directed motorists at an intersection in northern Mexico and then went to a nearby house and killed six men.
A Nuevo Leon state police investigator says the assailants were traveling in several cars through the Monterrey suburb of Guadalupe when they attacked the officer.
The investigator says the six men where killed at a house where drugs were allegedly sold. The investigator spoke on condition of anonymity because he is not allowed to discuss the case,
Monterrey's metropolitan area has seen a spike in drug violence since the split last year between the Gulf and Zetas drug cartels. The fight has killed more than 1,600 people in that region.