The bullet-riddled bodies of three Mexican environmental inspectors were found on a mountain highway a day after the men had set out to investigate reports of toxic waste contamination by a Canadian mining company, government officials have reported.

The victims, who were found dead on May 21, included two inspectors from the Federal Prosecutor’s Office for Environmental Protection (Profepa) and a collaborator of the National Commission for Natural Protected Areas (Conanp), Profepa said in a press release. A local resident who had filed the pollution complaint with the environmental authorities and who accompanied them on their inspection was also killed.

The victims’ bodies showed signs of torture and multiple bullet wounds, the Federal Attorney General’s office said in a statement. They were half-naked and partially buried along a roadside in the municipality of Temascaltepec, Mexico State. Police also discovered the inspectors’ jeep abandoned in the municipality, a mineral-rich area of dense pine forests 140 kilometers (87 miles) north of Mexico City.

Narcotraffickers to blame?

The deaths come amid a raft of murders of anti-mining activists in Latin America. The Federal Attorney General’s Office declined to comment on the news reports or on the possible motives for the killings. But local newspapers reported that the inspectors had discovered chemicals used in making synthetic drugs, and were likely murdered by narcotics traffickers.

Mexico is embroiled in an escalating drug war that has claimed more than 10,000 lives—including scores of police and soldiers—since President Felipe Calderón unleashed an unprecedented military offensive against the narcotics gangs in January 2007.

The Temascaltepec case would mark the first time Mexican environmental inspectors have been targeted, according to officials at Profepa, the enforcement arm of the National Resources and Environment Secretariat. Profepa says the inspectors were investigating alleged toxic chemical leaks at a gold and silver mine owned by Genco, an Alberta-based mining company.

Wayne Moorhouse, Genco’s chief financial officer, says the company was not aware of any environmental complaints regarding the mine. “We will have no further comment to make,” he wrote in an e-mail.

Environmental activists demanded that authorities do a better job of protecting environmental inspectors. “Profepa should develop a much more sophisticated intelligence and security system, as well as more diligent and responsible operations,” said the Mexican Center for Environmental Law (Cemda).

A Profepa official, who declined to be quoted by name, says agency inspectors don’t carry weapons, but have faced threats or attacks in the past and are often accompanied by police escorts. It wasn’t clear why the inspectors in Temascaltepec had set off unprotected.

Though it remains unclear whether the killings were carried out by drug traffickers, opponents of mine oversight or others, the murders come amid growing evidence of coercion in environmental disputes. In several cases, the disputes that have turned violent have involved mining sponsored by foreign corporations.

Violence is growing

In 2009, Mariano Abarca, a prominent anti-mining activist in Chiapas state, was shot dead outside his house. At the time, he was leading protests against a barite mine run by Blackfire Exploration, a joint Mexican and Canadian venture. Several mine employees were arrested in connection with the murder, but the company denied responsibility.

After Abarca’s death, Chiapas environmental officials closed the mine, citing company violations such as building roads without permission, polluting and causing toxic emissions. Blackfire is now threatening to sue the Chiapas government for US$800 million in damages, alleging violations of the North American Free Trade Agreement, according to news reports.

Separately, Francisco Gabino Quiñónes, an indigenous activist in Jalisco state, was murdered in 2006 after staging a campaign against the Peña Colorada iron mine in the state. The mine is owned by Mittal-Arcelor Steel Company, one of the world’s largest steel manufacturers, and Ternium Hylsa, the Mexican branch of the Latin American multinational Ternium. Gabino was found tied, with his throat slit and torture marks on his body, according to a March 2007 report by Hina Jilani, former UN special representative for human rights.

Then, in 2008, Dante Valdez, an environmental activist and schoolteacher, was attacked by workers at a gold and silver mine in Chihuahua state. The mine, run by Vancouver-based Minefinders Corp., had sparked the opposition of communal farmers, who accused the company of polluting their land.

Said Cemda President Gustavo Alanís Ortega, in a prepared statement: “Faced with these violations and the growing climate of insecurity, we demand the resolution of all these cases, the vast majority of which have ended in impunity.”