Gunmen entered a busy Nuevo Laredo plaza and laid out the nude bodies of four slain men next to their severed heads on a sheet according to Mexican police

The sheet had a message apparently signed by members of the Gulf drug cartel that was aimed at a rival gang. The gunmen arranged the macabre scene in full view of horrified pedestrians in the busy downtown area. With a population 350,000, Nuevo Laredo is one of the busiest commercial crossing points of goods from Mexico into the United States. It borders Texas. The Gulf cartel is engaged in a bitter war to control lucrative drug-smuggling routes with the Zetas, its former allies, a group made up of former military commandos. More than 36,400 people have been killed in Mexico's drug wars since 2006.