A pack of dogs attacked and killed an American Indian woman on a reservation in central Wyoming, officials said Monday. Some in the Eastern Shoshone Tribe she was a member of are skeptical of her cause of death.

"The tribes have ordinances and deal with dogs running around as any government does," said Kimberly Varilek, attorney general of the Eastern Shoshone Tribe, which shares the 2-million acre Wind River Indian Reservation with the Northern Arapaho Tribe in Wyoming, ABC News reports via AP.

"It's not really been an issue, we've not had a series of dog attacks or anything like that against people," Varilek added, explaining that this was the first time anyone with her tribe had heard pf such an attack. It remains unclear where the dog pack might have come from.

Mark Stratmoen, chief deputy Fremont County coroner, said 40-year-old Deanne Lynn Coando of Fort Washakie died at a Riverton hospital of hypothermia and loss of blood. He said she suffered serious injuries suffered in the attack on Wednesday by multiple dogs.

No one witnessed the dog pack attack, which has left some tribal officials shocked and skeptical.

"There may be some skepticism because it's so unheard of," Varilek said.

Sergio Maldonado, Sr., a member of the Northern Arapaho Tribe, said he had not heard of packs of dogs threatening people on the reservation. But he did note that it's common to see dogs that are hungry and cold.

"I don't mind sharing with you my observation that we have too many dogs on the reservation, probably cats, too," Maldonado said.

"It's not a problem safety wise for people and livestock," he added. "I haven't heard of anything like that."

Stratmoen also said he was not aware of any other fatal dog attacks in the area. Wyoming officials urged the public to watch for any aggressive dogs and report problems to law enforcement.

The investigation into the death of Coando is ongoing.