Prosecutors in Mexico's most violent state said seven men have been shot to death at a mechanic's shop.
The shootings occurred late Monday in the north-central state of Guanajuato, but were reported late Tuesday. The state prosecutors' office said the shop specialised in repairing motorcycles.
Guanajuato has Mexico's highest number of homicides, and has been the scene of turf battles between the Jalisco drug cartel and local gangs.
There was no immediate information on a possible motive in the shootings, but such attacks in Guanajuato in the past have been related to rivalries between drug gangs or street-level drug dealing.
The battle for control of Guanajuato, and industrial and farming hub, have continued despite increased efforts by police and the National Guard to contain the fighting.
In recent months, the Jalisco cartel kidnapped several members of an elite state police force, tortured them to obtain names and addresses of fellow officers and began hunting down and killing police at their homes, on their days off, in front of their families.