Last month, 15 people were killed in the state of Guerrero after gunmen attacked security forces
Nine people have been killed in southern Mexico in a shootout between two groups using high-powered weapons, authorities said on Thursday.
Several organized crime groups dedicated to trafficking drugs operate in the area and often clash over control of supply routes.
The confrontation occurred on Wednesday on a highway in a rural area in the state of Guerrero, the local attorney's office said in a statement.
"The deceased are close to Zenen Nava Sanchez, leader of the criminal group Los Rojos," it said, adding that an investigation had been launched into the incident.
A long-running dispute for territory between Los Rojos and a rival gang has left more than a thousand people dead and centred on a town some 10 kilometres from where the firefight took place, according to local media.
Experts at the site retrieved 50 bullets used in high-calibre weapons like the AK-47 assault rifle.
Last month, 15 people including a soldier were killed in the same state after gunmen attacked security forces.
The violence underlined the struggles of leftist President Andres Manuel Lopez Obrador to rein in crime since he took office last December.