Forty-nine dismembered bodies placed in plastic bags were found on a motorway near Monterrey in northern Mexico, prosecutors in the Nuevo Leon state said.
The bodies have been identified as 43 male and six female bodies.
Military officials and representatives of the local and central government have arrived at the site. Experts are examining the scene and the bodies.
In a separate incident, 15 bodies hidden in two cars were discovered in the Jalisco state on Wednesday.
In 2006, Mexican authorities declared a war on organized crime in the country. Since then, about 47,500 people have died in feuds between drug cartels and in clashes with police, according to official statistics.