Law enforcement in South Dakota are investigating after a pack of feral dogs fatally mauled a 9-year-old boy on an Indian reservation last week.

The boy, whose identity has not yet been released, was found beside a bike in the city of Eagle Butte suffering from injuries that “may have contributed to his death," Cheyenne River Sioux Tribe Chairman Ryman LeBeaf wrote in a statement released over the weekend.

The city is in Dewey and Ziebach counties on the Cheyenne River Reservation about 165 miles northeast of Rapid City.

Cheyenne River Sioux Tribe police Chief Charles L. Red Crow told USA TODAY officers were dispatched on Friday to a report of a male on the ground. Arriving officers, Crow said, found the boy unresponsive with multiple injuries to his body consistent with animal bite marks.

The boy was later identified by family, the chief said.

"We discovered that there were four dogs that attacked and killed him," Crow said Wednesday.

It was not immediately known if any of the dogs involved in the attack were located.

"With heavy hearts, we confirm that this Wakanyeja lost his life due to an attack by several feral dogs,' the police department posted on its Facebook page. "Our hearts are heavy and our deepest condolences go out to the family and friends that have suffered this tragedy."

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Autopsy to determine child's cause of death

An autopsy was completed on Tuesday, Crow said, and the preliminary results show the boy's cause of death was due to an animal attack.

News of the boy's death drew condolences on the department's social media post.

"Prayers for this little boy who journeyed to the spirit world way too soon, to his family and friends left to mourn his passing and to the entire Cheyenne River Nation as we come to grips with this devastating tragedy," one Facebook user posted.

Another person posted: "A preventable tragedy! My heart goes out to this little boy and his family."

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"We mourn with all relatives impacted," LeBeau wrote in the statement.

Animal control to patrol looking for dogs off leash

As a result of the attack, in an updated release, LeBeau wrote animal control officers would be dispatched to pick up collared and uncollared animals not tied up, tethered or in a fenced yard.

Collared animals will be held for 72 hour at the local animal shelter then "would be processed."

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.