CAGAYAN DE ORO CITY — A 52-year-old grandmother died after allegedly taking the same rat poison she had earlier force-fed to her four-year-old granddaughter in Purok 10, Poblacion, Don Carlos, Bukidnon, on Friday.

Police Lt. Rufina Bayarcal, deputy chief of the Don Carlos Municipal Police Station, confirmed the grandmother’s death Friday afternoon.

Police said the incident occurred about a week after the child’s mother was allegedly killed by her live-in partner, leaving the four-year-old in the care of her grandparents.

The grandparents were reportedly still mourning the mother’s death when a quarrel between the couple prompted the grandfather to leave the house, leaving the child with her grandmother.

The grandmother allegedly became distraught and turned her anger toward the child.

Police said she mixed zinc phosphide, a rat poison, with milk and force-fed it to the child, who died minutes after ingesting the substance.

The grandmother then drank the remaining poison and collapsed inside the house.

Neighbors rushed both victims to a hospital, where the child was declared dead on arrival. The grandmother later died while undergoing treatment.

Police are conducting a follow-up investigation and have identified the grandfather and the child’s father as persons of interest in the alleged murder-suicide case.