The public’s help is sought by Oregon officials to go after the person or people behind the poisoning of eight wolves earlier this year in the eastern part of the state.

In a news release Thursday, the agency said the killing of the five Catherine Pack in Union county members has been probed by the Oregon State Police, as well as the three other wolves from separate packs, ABC News reported.

“To my knowledge this is the first wolf pack to be killed by poison in Oregon,” OSP in Salem’s Capt. Stephanie Bigman said. “To my knowledge there are no suspects. All investigative leads have been exhausted and that is why we are reaching out to the public for assistance.”

The news has shocked wolf advocates.

Defenders of Wildlife in Portland member Stristi Kamal said it was “horrific”.  “This is quite clearly an intentional and repeat offense,” Kamal said, adding that only 170 wolves are within Oregon borders. The death of the eight “is so egregious.”

“The poisoning of the Catherine wolf pack is tragic and disgusting” Center for Biological Diversity staff attorney Sophia Ressler said. “No wolf should have to suffer such a fate. Awful events like this show how much more work is needed for us to coexist with these vitally important animals.”

A total of $26, 000 in rewards was put up by a group of conservation and animal protection groups on Thursday for anyone who can give information regarding the poisonings.

Included in the groups that offered the rewards were the Cascadia Wildlands, the Center for Biological Diversity, Oregon Wild, The Humane Society of the United States, Predator Defense, Northeast Oregon Ecosystems, and WildEarth Guardians.

Several places in the country have lost their wolves in the 1930s due to the poisoning and trapping campaigns of the government.

Six of the states in the Northern Rockies and Pacific Northwest were home to 2, 000 wolves after 1995 when they were reintroduced in Yellowstone National Park and Idaho.

But the animal stays absent across the majority of its historical range. According to wildlife advocates, there is a need for continued protection in order for the animal to continue its expansion in Colorado, Oregon, California, among other states.