ACAPULCO, Mexico -- Investigators searching clandestine graves have found 32 bodies and nine human heads in the southern Mexico state of Guerrero, where authorities say they are battling a wave of drug gang violence.

The grisly discoveries came in the municipality of Zitlala, where a drug gang had set up a rural camp where it held kidnap victims and disposed of its victims’ bodies.

When a joint military-police patrol happened on the camp earlier this week, it found a kidnapped man and what appeared to be clandestine burial pits. Initially investigators reported finding a dozen bodies, but after days of digging, they discovered a total of 32 bodies in 17 pits.

Get Breaking News Delivered to Your Inbox

The camp is near the area where nine decapitated bodies were found dumped on a roadside last week. The nine heads found in coolers at the camp may belong to those bodies, investigators said.

The area has been the scene of turf battles between two rival drug gangs - the Rojos and the Ardillos - who engage in extortion, kidnappings and killings. But in recent weeks the violence has spread to other areas, apparently as a result of turf battles between two or three other gangs, including the La Familia and Guerreros Unidos gangs, and a group known as the Tequileros.

Gov. Hector Astudillo condemned what he has called the wave of “barbarism and savagery,” and his office said called the situation “a public disturbance caused by organized crime.”

Roberto Alvarez Heredia, spokesman for the Guerrero Coordinating Group, said soldiers were combing the area to see if there are any more clandestine graves. Investigators were working to identify the bodies and the killers.

Guerrero has seen an upsurge in gang-related violence. The government announced on Monday that it is stepping up the use of joint police-army patrols in areas known to be particularly violent.

But many towns have formed their own vigilante “community police” forces to fight the gangs.

Residents of the town of Ajuchitlan, where about a dozen residents were kidnapped last week, had pledged to fight the gangs on their own.

But Astudillo announced that 200 Guerrero state police, with reinforcements from the neighboring state of Michoacan, had been assigned to the remote mountain area to try to find the missing men.

And in Tierra Colorada, closer to the resort of Acapulco, rival vigilante groups have been engaged in a series of battles for control of the town, leading to fears the vigilantes may be taking sides in the gang wars.

The largely rural, impoverished state had 1,832 reported homicides in the first 10 months of 2016. If that rate continues unabated, Guerrero would be on track to have a homicide rate of about 60 per 100,000. That would rival the recent peak year of violence in the state, in 2012, when there were about 68 homicides per 100,000 inhabitants.