Mexican authorities have found at least 17 bodies down a ravine in the violent southern state of Guerrero.
"There were nine complete bodies and eight half-burned," an attorney-general's official said on condition of anonymity, adding that they were found between December 8 and 11 in the village of Chichihualco.
The identities of the corpses, their ages and gender are unknown. Officials also do not know how long ago they died.
The state of Guerrero has suffered years of drug cartel violence as gangs grow opium poppies in remote mountains and battle for control of heroin trafficking routes.
Across the region, clandestine graves are often found with one or several bodies inside.
It is in Guerrero where 43 trainee teachers were abducted by corrupt police in the city of Iguala in September 2014 and, according to prosecutors, handed over to a gang that killed them and incinerated their bodies.