Five corpses wrapped head to toe in white sheets were found early Friday on a highway in the northern Mexican city of Saltillo, victims of suspected gang-related slaying.
The attorney general's office of Coahuila state said three of the bodies were hung by rope from a bridge and two were on the ground. All were male and lacked identification.
A message in a style associated with drug cartel murders was found nearby, officials said, though they did not disclose the contents of the message.
Police and the attorney general's office are investigating the deaths, a spokesman for the office said. The cause of death for the five men was still being established, the spokesman added.
Mexican President Enrique Pena Nieto, who took office in December, has vowed to curb the drug-related violence that raged under his predecessor, Felipe Calderon.
Calderon launched a military offensive against drug cartels when he took office in late 2006, but instead of reducing the violence, it increased. In December, the Mexican government estimated that some 70,000 people had died as a result of the drug war during Calderon's six years in power.
Though killings have fallen in parts of Mexico over the last 18 months, Coahuila, which has a long border with the United States, has become one of the epicenters of the violence.