Mexico is cementing its reputation as one of the deadliest places in the world for environmental and land defenders, human rights activists have warned after the latest murder of a prominent indigenous rights campaigner.

The body of Julián Carrillo, a member of the Alianza Sierra Madre organisation, was found with multiple bullet wounds in the mountains of Chihuahua state on the evening of 24 October.

He was killed a few weeks after his community of Coloradas de la Virgen registered opposition to a mining concession that they say was located in their territory without their permission, according to Amnesty International.

Carrillo had received multiple death threats. In the last two years, five members of his family have been killed, as have numerous other members of Alianza Sierra Madre, including the Goldman environmental prize winner Isidro Baldenegro López. Only one of the killers has been identified by police and no arrests have been made, says Amnesty.

Mexico is rapidly becoming a killing ground for activists, particularly those in indigenous communities. In 2017, 15 defenders were killed (a more than fivefold rise over the previous year), pushing the nation up from 14th to fourth place in the grim global rankings collated by the watchdog group Global Witness.

“Julián’s murder is emblematic of the threats facing defenders across Mexico: the imposition of natural resource exploitation on to communities without their consent, widespread violence fuelled by ongoing impunity, and a governmental protection unit consistently failing groups of activists at risk in rural areas,” said Ben Leather of Global Witness, who called on the president elect, Andrés Manuel López Obrador, to hunt down the killers, protect the family and address the root causes of the rising death toll.

While narco gangs are usually blamed, the state is often complicit. Senior politicians receive bribes and kickbacks for granting lucrative mining and logging concessions on indigenous land. When local communities resist attempts to clear their forests, pollute their rivers or destroy their crops, they are met with violence and assassinations.

Isela Gonzalez of Alianza Sierra Madre said: “It’s very sad. Julian is irreplaceable. He was very important in the fight for indigenous rights and the environment.”

Amid the grief and anger, she said his colleagues and community hoped the death would prompt an investigation of how the threats and killings are linked to the mining companies.

On Friday, she met government officials and called for the four mining concessions in the territory to be cancelled, for the perpetrators and masterminds of the killing to be brought to justice and for extra security for the Coloradas de la Virgen community under the state protection system.

“We are being exterminated with impunity because of the push for mineral resources that is destroying communities and the environment,” she said, and called for support from people and governments in other countries.

Gonzalez told the Guardian earlier this year: “This is about the government giving permits to exploit everything recently. And then you have communities who don’t want to sell the land, they have a different vision of things, they want to keep things as they are.”