(Reuters) - Nine staff members at a state prison in Nebraska were injured during an altercation with inmates on Wednesday, a state correctional services spokeswoman said.

The staff members were taken to hospital, treated and released after the incident that put the Lincoln Correctional Center on lockdown, Nebraska Department of Correctional Services spokeswoman Dawn-Renee Smith said in a statement.

The staff members were assaulted by inmates who refused to return to their housing units, she said.

It was unclear if any inmates were injured during the incident.

(Reporting by Brendan O'Brien in Milwaukee; Editing by Paul Tait)