Failure to protect a nature reserve for the endangered and elusive Siberian tiger has led to public prosecutors suing a government department in China’s remote northeast.

The lawsuit revolves around an allegedly illegal granite mine operating in the forests near Hunchun, a city in Jilin province. The procuratorate argues the mine causes habitat loss for the tiger population.

The city’s procuratorate sued the city’s land and resources bureau — the body responsible for mining operations — on Friday. Authorities publicized the case on Tuesday.

The mine lies at the bank of the Tumen River, which straddles the borders between China, North Korea, and Russia. The area is the habitat of the Siberian tiger — an endangered species, according to the International Union for Conservation of Nature. In 2001 China declared 108,700 hectares of forest a protected area. (One hectare is roughly 1.5 soccer fields.)

According to Hunchun’s procuratorate, the mine is owned by a married couple and has been in operation since April 2014. The owners had cut down trees in an area of more than half a hectare without government approval, it said, and they also illegally discharged waste into the river.

In early March, the procuratorate urged the land and resources bureau to put a stop to the mining activities. The bureau replied three months later to say that they had noticed the illegal mine, but had not taken any action.

He Chunlin, policy and law director at Hunchun’s land and resources bureau, told Sixth Tone the suit was very unexpected. “We received the notice from the procuratorate in March, and in April and May we worked with the procuratorate and public security bureau to investigate,” he said.

The case was complicated, He continued, because the husband had passed away in January. In addition, the bureau had noticed the mine as early as 2015, though the couple at the time said they were removing rocks in danger of falling on a nearby road, and had a document stamped by the military to prove it. The person who stamped the document, however, has since left the defense department.

Though environmental organizations frequently sue authorities for violating environmental laws and regulations, it’s uncommon for local procuratorates to file lawsuits against government departments.

Siberian tigers, the world’s largest cats, once roamed the forests of northern China, but they nearly went extinct in the 1950s due to deforestation and poaching. Currently, the animals’ population in China is estimated at about 20. According to a recent survey, some 540 of the tigers live in Russia.

The Chinese government has undertaken various conservation efforts to improve the Siberian tigers’ numbers, such as banning hunting and commercial logging in its natural forests. People living in the tigers’ habitat say encounters with the animals have become more frequent in recent years.

Zhang Chunlin, a voluntary ranger in Hunchun, told Sixth Tone that some tigers have even been seen wandering into villages, and that many challenges still exist. Every winter, Zhang searches the woods for traps and disables them. “Some people like to hunt deer and other small animals,” said Zhang. “But these animals are also food for the tigers.”

Additional reporting by Lin Qiqing.

(Header image: Park rangers patrol Siberian habitat near Hunchun, Jilin province, Dec. 15, 2005. Zhang Ke/VCG)