Investigators found the bodies of at least 13 people in five clandestine graves outside Zumpango, a community in the southern Mexican state of Guerrero, officials said.
Some 1,000 people have fled their homes in southwestern Mexico after gunfights erupted in their villages.
Gunmen killed nine state police officers and wounded a tenth law enforcement agent in the southern Mexican state of Guerrero, prosecutors said.
The victims were members of political parties and were heading to a rally, a report said.
Tuesday`s earthquake caused about 60 houses to collapse and damaged about 800 more homes.
Gunmen ambushed and killed
12 police officers who had been sent to investigate the beheadings of 10 people in southern Guerrero state.
Day in Pics: 30th August
August 30, 2014
Famous Ganesh Pandals in Mumbai