Authorities said on Tuesday they were still analysing the dismembered body parts to try and identify the number of people who had been killed.
They confirmed at least seven bodies had been found as well as five bags of body parts, some of which were discovered in cooler boxes.
Messages had also been left on the remains, and local media reported there could be as many as 12 victims.
Gerardo Palacios, the head security official for Nuevo Leon state, said the killings appeared to be related to an internal dispute within a drug cartel based in neighbouring Tamaulipas. The Gulf and Northeast cartels operate there but he did not specify the group he was referring to.
“What we see here is an internal purge within an organised crime group based in Tamaulipas, because of some acts of disloyalty within the group,” Palacios said.
Drug cartels in Mexico often leave dismembered bodies on streets, commonly with banners threatening officials or rival gangs.
The grisly discoveries recalled the 2010s when the city was engulfed in a violent turf war between drug cartels and bodies were left in the streets or hanging from bridges.
Monterrey has since evolved into an industrial powerhouse and officials have been wooing foreign investors, including electric car giant Tesla.
Mexico has recorded more than 420,000 murders — most of them blamed on organised crime — since the launch of a controversial military operation to combat drug trafficking in 2006.
Photos of the supposed messages circulating in the local press and on social media suggested the Northeast Cartel had carried out the murders as retribution for alleged infiltration of the group. The attorney general’s office did not confirm the authenticity of the photos.
