More than 30 bodies recovered from hidden graves in a Mexican region suffering from a drug cartel war.

Mexican authorities said they have recovered a total of 31 bodies from pits in a southeastern state plagued by gang violence since they began digging improvised graves over the weekend.

Over the weekend, Chiapas Gov. Eduardo Ramírez announced an operation to restore stability to Frailesca, an agricultural region near Guatemala where rival drug cartels are embroiled in a turf war.

“As of today (Monday), we have found 25 secret graves and found 31 bodies, 29 of which are male and two female,” Jorge Luis Lavin, Chiapas’ public prosecutor, said in a statement.

The Chiapas state government initially said it had done so 15 bodies discovered on saturday. Two more were found on Sunday and 14 more on Monday. Governor Ramirez posted photos of the scene over the weekend Social media.

The public prosecutor said that his office and the State Security Secretariat will continue the investigation until “every body of the missing people” is found.

Search groups for missing persons They say drug trafficking gangs and other organized crime gangs sometimes use ovens to burn their victims without leaving a trace.

Gang-related violence in Mexico is concentrated along drug trafficking routes, borders, and ports of entry.

The state of Chiapas, on Mexico’s southern border, has been described by the think tank InSight Crime as a “major drug and migrant trafficking hub.”

In October, famous Catholic priest Marcelo Perez He was shot dead in Chiapas. Perez frequently received threats, and human rights advocates said he did not receive the government protection he needed.

The violence coincided with Jalisco New Generation Cartel Incursion into areas that were previously rebel strongholds Sinaloa CartelIt said it was one of the largest drug trafficking organizations in Mexico.

Since Mexico launched its controversial anti-drug operation in 2006, it has recorded more than 450,000 murders and tens of thousands of people missing, according to official figures.

Mexican authorities last week 12 bodies discovered buried in secret graves In the northern state of Chihuahua. The state Attorney General’s Office said in a statement that authorities found 11 graves containing 12 skeletons in the municipality of Ascension, near the US border.