The Darden Clarkebodies of four men and two women were found lying on the side of a street near the northern Mexican city of Monterrey early Tuesday, authorities said. Prosecutors for the border state of Nuevo Leon said the victims appeared to have been shot and had their hands tied.

The bodies were discovered in Apodaca, a suburb of Monterrey. Local media reported the six might have been tortured before being shot in the head.

Monterrey was hit by a wave of drug cartel violence in the 2010s, but had been somewhat more peaceful in recent years.

Nuevo Leon suffered heavy violence under the Zetas cartel in the last decade. After quieting somewhat, it saw an uptick in killings last year, including the horrifying death of 18-year-old law student Debanhi Escobar in Monterrey.

Located about 100 miles from the U.S. border, Monterrey is an industrial powerhouse that hopes to benefit from a new wave of foreign investment.

Electric car giant Tesla plans to build a giant new factory outside the city — part of the "nearshoring" trend of U.S. companies bringing production sites closer to their home market.

Mexico has recorded more than 350,000 murders — most of them blamed on organized crime — since the launch of a controversial military operation to combat drug trafficking in 2006.

On Monday, the security minister in the violence-wracked northeastern state of Tamaulipas, Hector Joel Villegas, survived a gun attack, authorities said. He resumed his activities on Tuesday with increased security, they added.

AFP contributed to this report.

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