Two minors were found dead in a forest in San Jose Del Monte, Bulacan on Wednesday.
Police identified the victims as Jennie De Vera, 11, and Lou Anderson Icalia, 8.
De Vera was found naked in a dense part of the mountainous village while Icalia was found lying face down.
The two victims sustained injuries in different parts of their bodies.
"Walang kapatawaran yung ginawa nya (perpetrator). Dahil durog ang mukha, nakakapanghinayang (What the perpetrator did was unforgivable. He shattered my daughter's face. Her death is a great loss for us)" De Vera's father, Endrigel, said in a GMA interview. He added that his daughter's face was beyond recognition after it was hit apparently with a rock.
Police said the two children were reported missing on Tuesday.
Icalia's sister Danica said in a News 5 interview that her brother was playing inside their house when De Vera came to pick him up.
The victims' relatives believe that the perpetrators asked them to go to the mountainous part of the village where they were killed.
"Nakita daw ng binata na umakyat daw ng bundok, may kasama daw na bata din (A witness saw my daughter go to the mountain with another child)," De Vera's mother, Maricon, said in News 5 interview.
Police said they are still waiting for the result of the autopsy performed on the victims' bodies to determine if De Vera was sexually abused as well as the cause of their death.
The victims' families are appealing for justice from President Duterte.