"They had injuries from burns and stabbings. None were serious and there were no deaths to lament," said Juan Carlos Manriquez, head of the prison guard service in the Valparaiso region.
He said a brawl broke out among inmates at the prison in Quillota, which houses an estimated 500 prisoners 80 kilometres north of Santiago.
During the fighting inmates set fire to their mattresses and hurled them outside their cells.
Another group of prisoners took advantage of the disturbances to riot in another part of the prison, Manriquez said.