One prisoner died and five were injured in a clash involving some 50 inmates in Guatemala, state prison authorities said.
Special forces of the Pavon Prison, located just outside the country's capital, intervened to regain control of the institution that houses some 4,000 inmates, prison system spokesman Rudy Esquivel told journalists.
He said the cause of the clash was under investigation, adding that victims showed signs of blows and wounds "presumably" caused by knives.
The prison was the scene of a July 2016 riot that left more than a dozen dead, including an ex-soldier imprisoned for killing a Roman Catholic bishop almost two decades ago.
The Guatemalan Penitentiary System administers 21 prisons nationwide with a maximum capacity of 6,809 prisoners -- but 22,574 people are currently in custody, according to official data.