Police found the bullet-riddled body of a man in this Mexican border city Tuesday alongside a sign accusing him of being a thief. It was the second such killing this month.

City police did not release the text of the sign, but said it referred to the unidentified victim as "another thief."

Eight days earlier, the body of a tied-up gunshot victim was found in the city next to sign reading: "This is what is going to happen to the damn thieves who steal cars with guns."

It was unclear who carried out the killings. Mexican drug gangs have been known to kill common thieves who operate on the gangs' turf.

In other violence, prosecutors in the northern state of Coahuila said the body of a 22-year-old soldier assigned to a local base had been discovered bound up and shot to death near the city of Torreon.

The killing took place just a day before President Felipe Calderon was scheduled to visit Torreon.

Since taking office in December 2006, Calderon has sent more than 45,000 soldiers to combat drug cartels whose turf battles have killed more than 10,750 people over the last 2 1/2 years.

In the Gulf of Mexico city of Poza Rica, in southern Veracruz state, police reported that five "narco banners" signed by the La Familia drug cartel appeared strung over roadways Tuesday accusing Mexico's top police official of abuses and demanding that authorities not persecute the families of cartel members.