TEHRAN, Young Journalists Club (YJC) - The riot spun out of a brawl among prisoners in the Pavoncito maximum security prison, said prison spokesman Rudy Esquivel.
Volunteer firefighters reported that four people were transferred to hospital and at least seven inmates died from bullet wounds, according to local newspaper, Prensa Libre.
"The incident happened in an area of isolation. No guard was injured or deceased," Esquivel told local media.
Authorities have since retaken control, he added.
At least 12 inmates died in a riot in July 2013 at the same prison, in the town of Fraijanes, about 12 miles from the Guatemalan capital.
The reason for the fight and the names of the victims was not immediately known.
Source: Reuters