Forty-nine bodies with their heads, hands and feet hacked off have been found dumped on a northern Mexico highway in what appeared to be the latest carnage in the escalating war between Mexico's two dominant drug cartels.
Authorities discovered the bodies before dawn on Sunday lying in a pool of blood at the entrance to the desert town of San Juan, on a highway leading from the metropolis of Monterrey to the border city of Reynosa. A white stone arch welcoming visitors was spray-painted with black letters: "100% Zeta".
Nuevo Leon state security spokesman Jorge Domene said the 43 men and six women would be hard to identify. The bodies were being taken to Monterrey for DNA tests.
49 mutilated bodies found in Mexico
The victims could have been killed as long as two days ago at another location, then transported to San Juan, a town in Cadereyta municipality about 105 miles west-south-west of McAllen, Texas, and 75 miles south west of the Roma, Texas, border crossing, state attorney general Adrian de la Garza said.
He said he did not rule out the possibility that the victims were US-bound migrants, but it seemed more likely that the killings were the latest salvo in a gruesome game of tit-for-tat in fighting among brutal drug gangs.
"This is the most definitive of all the cartel wars," said Raul Benitez Manaut, a security expert at Mexico's National Autonomous University.
Mass body dumpings have increased around Mexico the last six months as the fearsome Zetas gang goes head to head with the powerful Sinaloa Cartel, led by fugitive drug lord Joaquin "El Chapo" Guzman.
Under President Felipe Calderon's nearly six-year assault on organised crime, the two cartels have become the largest in the country and are battling over strategic transport routes and territory, including along the northern border with the US and in the Gulf coast state of Veracruz.
In less than a month, the mutilated bodies of 14 men were left in a van in central Nuevo Laredo, 23 people were found hanged or decapitated in the same border city and 18 dismembered bodies were left near Mexico's second-largest city, Guadalajara.
The government's success in killing or arresting cartel leaders has fractured some of the big gangs into weaker, quarrelling bands that in many cases are lining up with either the Zetas or Sinaloa. At least one of the two cartels is present in nearly all of Mexico's 32 states.