CAIRO, Sept. 8 (Xinhua) -- At least 25 people were injured in a prison riot sparked by the death of an inmate in southern Egypt on Monday, the Egyptian MENA news agency reported.

    Most of the wounded, including 21 prisoners and four warders, suffered light and medium injuries in the riot in the southern Egyptian city of Assiut, some 330 km south of Cairo, the Interior Ministry said in a statement.

    When a clash erupted on Monday among a number of inmates, the prison guards intervened to control the situation and isolated the rioters in solitary confinement cells.

    But "one of the inmates died in the process," which triggered rumors among the prisoners that the inmate was tortured to death, said the statement.

    The prisoners gathered in the yard of the jail and tossed stones at the jail's facilities, said the statement, adding that some of them tried to escape.

    Police forces fired tear gas bombs and opened fire in the air to calm down the situation. An investigation to the riot is underway.