That news served as a wake-up call to Mexicans that drug traffickers have penetrated the country's economy at unheard-of levels, becoming true Mafia-style organizations, ready to defend their mines at gun point.
Three Michoacan state detectives were wounded in an ambush earlier this week when they were traveling to investigate a mine taken over by criminals. When reinforcements arrived, those officers were also ambushed, part of a string of attacks on police in Michoacan on Wednesday and Thursday that left two officers dead and about a dozen wounded.
The Knights Templar cartel and its predecessor, the La Familia drug gang, have been stealing or extorting shipments of iron ore, or illegally extracting the mineral themselves and selling it through Pacific coast ports, said Michoacan residents, mining companies and current and former federal officials. The cartel had already imposed demands for "protection payments" on many in the state, including shopkeepers, ranchers and farmers.
But so deeply entrenched was the cartel connection to mines, mills, ports, export firms and land holders that it took authorities three years to confront the phenomenon head-on. Federal officials said they are looking to crack down on other ports where drug gangs are operating.
"This is the terrible thing about this process of (the cartel's) taking control of and reconfiguring the state," said Guillermo Valdes Castellanos, the former head of the country's top domestic intelligence agency. "They managed to impose a Mafia-style control of organized crime, and the different social groups like port authorities, transnational companies and local landowners, had to get in line."
Valdez Castellanos said that even back in 2010, the La Familia cartel would take ore from areas that were under concession to private mining companies, sometimes with the aid or complicity of local farmers and land owners, then sell the ore to processors, distributors and even, apparently, foreign firms.
Mexico's Economy Department said the problem was so severe that it prompted the government to quietly toughen rules on exporters in 2011 and 2012 and make them prove they received their ore from established, recognized sources.
Many exporters couldn't. In 2012, the department denied export applications from 13 companies, because they didn't meet the new rules. And the problem wasn't just limited to Michoacan, or the Knights Templar cartel.
"Since 2010, evidence surfaced of irregular mining of iron in the states of Jalisco, Michoacan and Colima," the department said in a statement to The Associated Press.
"That illegal activity was encouraged by the great demand for iron by countries such as China, to develop their industries," according to the department. "Many trading companies began to build up big stockpiles of legally and illegally obtained iron (ore), that was later shipped out for export."
A Mexican federal official, who was not authorized to speak on the record, said the cartels would use a combination of threats and outright theft to get the ore from mines. He said the nexus between the cartels and export companies was key.
"They extort the merchandise from mining companies and then export it through legal companies, or they rob trucks full (of ore) that later turn up in a legal manner," the official said.
Ofelia Alcala, a resident of the Michoacan mining village of Aquila, said that since 2012, the Knights Templar cartel has demanded residents hand over part of the royalty payments from a local iron ore mine operated by Ternium, a Luxembourg-based consortium. Alcala, a member of a self-defense group that rose up in arms in Aquila this summer to kick the cartel out, said the cartel also had been hiring people to extract the ore without permits, and then exporting it through another Pacific coast port, Manzanillo.
"They weren't content with getting our money and robbing our trucks, so they began secretly extracting our minerals," said Alcala.
Ternium said in a statement that it has received reports of irregular mining near its operations in Aquila.
"Those have been passed on to the appropriate authorities," the company said in a statement.