Mexican authorities discovered 20 bodies on Wednesday, 17 of them burned, near the city of Nuevo Laredo, close to the U.S. border, a security official said, quoted by Reuters.

Five burned vehicles were also found near the bodies in the town of Miguel Aleman, across the Rio Grande from Texas in the northern state of Tamaulipas, the official said in a statement, without providing details.

Tamaulipas has become one of the most violent states in Mexico, convulsed by gangs fighting to control drug trafficking, extortion rackets and the exploitation of migrants.

Hundreds of bodies in unmarked graves have been found in recent years in the aftermath of the decade-long drug war led by the military to battle the cartels, which led to increasingly bloody turf wars.