Six lions and 74 vultures were found dead near a national park in southern Tanzania this week after they were poisoned to death, authorities.

Permanent Secretary for Natural Resources and Tourism Gaudence Milanzi said on Friday the way the animals were killed suggested they had been poisoned by local herdsmen amid an escalating human-wildlife conflict in the country.

“I can confirm that six lions were poisoned in the wildlife management area just outside of the Ruaha National Park. We are investigating this incident,” Milanzi said.

“An investigation launched by the government has been able to arrest one suspect, with samples of the poisoned lions and vultures taken to the Chief Government Chemist Laboratory to identify the type of poison used,” he said.

Tanzania’s $2 billion tourism sector, which depends heavily on wildlife safari, is the biggest foreign exchange earner, but there are growing clashes between wildlife populations, farmers and livestock keepers.

Conservationists described the latest mass poisoning of lions and endangered vultures near the Ruaha National Park as a “devastating scene,” with the scavengers killed after eating a poisoned cattle carcass.

“Six lions… had been killed, apparently from poison, as they were all found close to a scavenged cattle carcass,” the Ruaha Carnivore Project (RCP), part of Oxford University’s Wildlife Conservation Research Unit (WildCRU), said in a statement.

“This event had additional tragic consequences, with dozens of critically endangered vultures found dead or badly affected,” the statement said.

“They eventually found 74 dead vultures as well as the six lions.”

Four other sick vultures were taken to the Ruaha National Park for treatment. One died shortly after arrival, but the others are doing well, it said.

“It appears as if someone poisoned a carcass after lions attacked cattle. Alarmingly, poisoning is a common response to conflict,” said the Ruaha Carnivore Project, which is monitoring lion populations in Tanzania.

In 2014, a herdsman near the Ikona Wildlife Management Area in Serengeti district in Mara region poisoned to death seven lions after they attacked his cows.