MEXICO CITY (Reuters) - As many as 12 bodies have been uncovered in hidden graves in Mexico's violent state of Guerrero, the state government has said, and authorities will continue to investigate on Thursday.

Cartels are battling over drug trafficking routes in the southwestern state, home to the beach resort of Acapulco.

Five bodies were found on Wednesday and seven on Tuesday, the state government said on its website, all located in hidden graves in the municipality of Zitlala.

Nine corpses with signs of torture were also found on Monday in the state, where the disappearance of 43 students in 2014 sparked a major human rights crisis for President Enrique Pena Nieto.

Pena Nieto's popularity has hit fresh lows over his handling of the economy, rising violence and perceptions of corruption.

(Reporting by Enrique Andres Pretel)