Eight bodies were found in Ecatepec, a suburb on the outskirts of Mexico City, on Thursday.
Reuters reported that six of the bodies, five men and one woman, showed “signs of torture.”
They were naked and their throats had been cut, a spokeswoman for police in Ecatepec was quoted as saying.
In another incident, the bodies of two men, aged between 18 and 22, were found in a nearby street with gunshot wounds, Reuters reported.
The Associated Press reported that the eight corpses were “bullet ridden.”
"Both incidents are being investigated by the homicide prosecutor's office, which immediately assigned personnel to conduct the corresponding investigation," the Mexico state Attorney General's Office was quoted by Spanish news agency EFE as saying.
Ecatepec is a poor suburb on the northern outskirts of Mexico City, with a population of around two million people.
Mass killings are relatively rare in the Mexican capital, which has been spared much of the drug-related massacres that have occurred in other parts of the country.
Nearly 60,000 people have been killed in drug-fueled violence since late 2006 when President Felipe Calderon stepped up a campaign against the country’s powerful drug cartels.
More from GlobalPost: Mexico passes law to fight money laundering