The bodies of nine men were found hanging from a bridge Friday in Nuevo Laredo, a border city in the northeastern Mexican state of Tamaulipas, officials said.

"The individuals were hung (early Friday) from a bridge at the intersection of Colosio Blvd. and the highway leading to Monterrey," capital of the neighboring state of Nuevo Leon, a security spokesman in Nuevo Laredo said.

The bodies bore signs of torture and the suspected perpetrators of the crime left a message whose content was not disclosed.

Prior to the discovery of the bodies, an armed commando had dragged several people from a bar and later set the establishment on fire. Investigators are trying to determine if those victims were the same people hung from the bridge.

In May, the bodies of five men and four women who were blindfolded and bore signs of torture were found hanging from another Nuevo Laredo bridge.

On that occasion, suspected members of the Los Zetas drug cartel said in a message that the victims were members of the rival Gulf mob who were killed for "heating up the plaza (drug-smuggling route)" and attracting the attention of the security forces with their attacks.

The Zetas have threatened to wipe out the Gulf organization, which has allied itself with the powerful Sinaloa gang - headed by Joaquin "El Chapo" (Shorty) Guzman - in a bid to seize control of the city, located across the border from Laredo, Texas.

These latest killings came on the heels of Wednesday's capture of top Gulf cartel boss Jorge Eduardo Costilla Sanchez, alias "El Coss," by Mexican marines. Not a single shot was fired in that operation in the northeastern port city of Tampico.

Costilla's detention left the Gulf mob - one of Mexico's oldest criminal organizations - without its two top leaders. On Sept. 3, marines captured Mario Cardenas Guillen, alias "El Gordo," who had headed another branch of that drug cartel.

These blows should exacerbate drug-related violence in Mexico, experts say, because the Zetas will look to seize control of areas still under the control of the Gulf cartel, which maintains its stronghold in the northeastern state of Tamaulipas and also operates in other parts of northern Mexico and the country's Gulf coast.

The Gulf cartel and the Zetas, its former armed wing, severed ties in 2010 and that split has sparked turf battles in northeastern Mexico that have left thousands dead.

That region is one of the flashpoints in a drug war that has left some 60,000 dead since President Felipe Calderon, whose term ends this year, took office in late 2006. EFE