A day after marines killed a powerful drug lord his rivals hung dozens of banners in cities across Mexico's Gulf coast with ominous messages gloating about his demise.
The signs, hung on pedestrian bridges and at other public places at the weekend but quickly taken down by the authorities, reinforced fears that the death of the Gulf cartel leader Antonio Ezequiel Cardenas Guillen will empower the Zetas, a gang of hitmen formed in the Nineties by renegade Mexican soldiers which has become one of the country's most feared drug gangs.
Formerly allies of the Gulf cartel, the Zetas went independent earlier this year, unleashing a turf battle along the north-eastern border with the US which has at times reached the level of all-out war.
Drug gangs used vehicles to erect roadblocks in Reynosa, a city across from McAllen, Texas, according to Twitter messages sent by the Reynosa city government warning the public to travel with caution. It was unclear if the roadblocks were related to the death of Cardenas Guillen; such blockades have become a near-daily gang tactic in north-eastern Mexico.
The Mexican navy has said that Cardenas Guillen, known as "Tony Tormenta" or "Tony the Storm", was killed on Friday during a two-hour shoot-out in an operation that involved 150 marines, three helicopters and 17 military vehicles.