Two vehicles containing 16 charred bodies were found early on Wednesday in Culiacan, capital of the violence-wracked northwestern state of Sinaloa, in what officials say is macabre message between rival drug gangs.
The vehicles were found about five kilometers (three miles) apart, Martin Gasteum, a spokesman for the Sinaloa state prosecutor's office, told the media by telephone.
"In the first (vehicle) 12 bodies were found, and in the second, four," Gasteum said.
Firefighters received emergency calls at dawn to put out the fire at the first vehicle, then got a call to put out the fire at the second car about ten minutes later, Gasteum said.
The coastal state is the home ground of one of Mexico's best-known drug lords, Joaquin 'El Chapo' (Shorty) Guzman, head of the powerful Sinaloa drug cartel.
A female body was found in the first vehicle, while one of the victims in the second vehicle had been decapitated and his head left on the ground, Gasteum said.
Preliminary reports show that the victims were first shot dead, then their bodies were driven to the site where the cars were set ablaze. "There were no signs of violence in the place where the bodies had been abandoned," Gasteum said.
Sinaloa Governor Mario Lopez Valdez said the violence could be 'a message between criminal groups'.
Four men were shot dead on Wednesday in a town some 25 kilometers (15 miles) north of Culiacan, but Gasteum said the incidents were unrelated.
Separately, the Mexican Army announced that on Tuesday it had confiscated 1.7 tons of marijuana after a driver and passengers abandoned a truck in Culiacan.
Sinaloa, on Mexico's Pacific Ocean coast, is on one of the busiest routes for illegal drugs moving north into the United States.