(Reuters) - Eight inmates and an officer were taken to hospital on Tuesday after they were injured during several fights at a jail in Chicago, fire and jail officials said.

The officer was hit by a food tray and several inmates were stabbed during the skirmish that broke out at about 7:30 p.m. at a maximum security Cook County jail in Chicago, a Cook County sheriff's spokeswoman said.

It was unclear what set off the fights at the jail that houses more than 1,000 male inmates southwest of Chicago's downtown, she said.

The injuries were non-life threatening, the Chicago Fire Department said on Twitter.

Several other inmates were treated for minor injuries at the jail, Chicago Fire Department spokesman Larry Langford told the Chicago Tribune.

(Reporting by Brendan O'Brien in Milwaukee; Editing by Tom Hogue)