Officials have still not identified skeletal remains of several people dug up last summer from a burial site discovered by a utility crew off Interstate 29 in North Sioux City.

The Sioux City Journal reports a state official says a preliminary investigation showed the bones belonged to about nine people, including an infant. Officials originally thought the remains to be those of three or four people.

Katie Lamie is burial program coordinator with the Archaeological Research Center of the South Dakota State Historical Society. She says the remains are now stored awaiting further study.

While their identities are a mystery, Lamie says it's been determined the remains are not Native American. Civil War-era buttons and coffin designs discovered during the dig suggest a date from 1865 through 1880.

The Associated Press contributed to this story