R Kelly has been attacked in prison.

Kells was sitting on his bed when another inmate came in and attacked him.

The inmate was apparently angry that the prison had been shut down because of protests on Kelly's behalf.   The fight didn't last long and it's unclear if it was broken up by another inmate or a guard.

Kelly, who's housed at the Metropolitan Correctional Center in Chicago, didn't suffer any server injuries. 

Kells is facing sex crime charges in New York and Illinois.