A den of six lions mauled to death at least two suspected rhino poachers on a wildlife reserve in South Africa.

Nick Fox, the owner of the Sibuya Game Reserve, said in a Facebook post that a field guide discovered human remains Tuesday afternoon in the reserve’s lion enclosure.

“We were shocked,” Fox told CTV News Channel Friday. “On a quick inspection around the site, once I saw human remains, I couldn’t let anyone get out of the vehicles even if they were armed. Lions were right there—metres away from us—at the time.”

Fox said that he found a high-powered rifle with a silencer, an axe, wire cutters and a backpack filled with water and food supplies near to the site, which led him to suspect that the victims were poachers.

“They were thinking of spending time in the reserve looking for the rhinos,” he said.

An anti-poaching dog alerted her handler on Monday morning that “something was amiss,” but the handler was not concerned because it is not unusual to hear lions at night, Fox wrote in the Facebook post.

“It now appears likely that the dog had been alerted by something else out of the ordinary coming from the lions,” the Facebook post said.

Fox said he alerted the Indalo Anti-Poaching Cluster and the local police, which are now combing the area for clues.

It is not yet clear how many suspected poachers were killed.

South Africa, which is home to an estimated 80 per cent of the world’s rhino population, is dealing with a poaching crisis. More than 1,000 rhinos were poached in 2017, according to figures from the environment ministry.

Poaching, Fox said, is “becoming more and more common in the area” because rhino horns are coveted and believed to be “more valuable than gold.”

His reserve lost three rhinos in March 2016, when poachers hacked off their horns.