MEXICO CITY (Reuters) - Attackers kidnapped and murdered 14 men and left their corpses in a Mercedes Benz van on a major highway in the state of San Luis Potosi in central Mexico, a prosecutor said Thursday.
The men were kidnapped Wednesday in the northern state of Coauhuila, where the vehicle was stolen in an armed robbery, an official from the attorney general's office of San Luis Potosi said. The corpses were found early Thursday morning.
The attack bore the hallmarks of drug cartels, but it was not immediately clear which group carried out the murders, or who the victims were, said the official, who asked that her name not be used for security reasons.
Later Thursday, federal police raided an alleged drug cartel safe house in San Luis Potosi's state capital, leading to an hour long shoot-out with gunmen, an official from the federal police said.
Mexico TV station Milenio showed amateur photos of students at a nearby university hiding under tables as the firefight raged.
The federal officer said several suspected drug traffickers were arrested following the shooting.
In 2011, a U.S. official was killed in an armed assault on his vehicle in San Luis Potosi.
Thursday's attack is the fifth time in recent months that 14 corpses have been dumped in Mexico, signaling the number may be some sort of code for drug traffickers.
In April, assailants strung up the corpses of 14 men in Nuevo Laredo, on the border with Texas. Coolers containing 14 men's heads were left on a city street the next month. In June, police found 14 corpses in a vehicle near the town hall of Mante, in Tamaulipas state, and another 14 on a road in neighboring Veracruz state.
There have been more than 55,000 gangland murders and execution style hits since President Felipe Calderon took power in December 2006 and declared a national crackdown on drug gangs.
Many of the victims have been identified as innocent civilians unconnected to the drug trade.
President-elect Enrique Pena Nieto takes power in December and has promised to reduce the rate of homicides and kidnappings.
(Reporting By Liz Diaz and Ioan Grillo; Editing by Vicki Allen and Stacey Joyce)