A series of murders targetting families, including children, has rocked Mexico in recent weeks.
This signals that drug gangs are willing to break the unspoken code of honor within the criminal underworld.
In total, 34 people have been killed, including several women and 10 children, since early July in three regions.
Last month, 19 persons, including 8 children, from three different families were gunned down in less then a week in Ciudad Victoria, the capital of northeastern state of Tamaulipas.
Authorities suspect that those massacres were linked to disputes between rival gangs in Tamaulipas, a region that has been besieged by drug cartel violence for years.
On July 18, seven shark fishermen from the same family were killed in the southern Pacific coast state of Oaxaca.
Authorities suspect, it may be linked to illegal activities at sea.
The Pacific is key route for drug trafficking.
The most recent massacre came on Saturday, when seven people from the same family, including two children, were shot dead in a small town in Southern Guerrero state.
While the motive is unknown, gangs are fighting for control of opium poppy production in the area.