A tornado struck the largest coal mine in the US while workers were in the midst of a shift change Friday in northeast Wyoming, injuring at least 8 people, officials said.

The tornado hit the North Antelope Rochelle Mine in Campbell County at around 6:20 p.m. MT Friday, according to county government spokesperson Leslie Perkins.

"It has been confirmed that the event happened during shift change," Perkins said.

Six people remain hospitalized at Campbell County Health and all are in stable condition, according to a hospital statement Friday night, and "anticipates treating and releasing all six patients."

One individual was transported for further care to the Memorial Hospital of Converse County in Douglas and another refused medical treatment, according to a Campbell County statement Friday night.

Mine operator Peabody Energy Corporation confirmed the facility sustained damage and its employees have been accounted for, their statement said.

"Operations have been suspended until we can fully assess facility damages and begin the process of restarting safe operations," the statement said. Power and gas has been shut off to the mine, county emergency officials said.

The North Antelope Rochelle Mine is the largest coal mine in the US by production, according to the US Energy Information Administration.