A 15-year-old housewife, Dausiya Abdulmumin, has killed her husband Saminu Usman, 27, and her younger brother, Muhammad Abdulmumin, 18.
The incident occurred in Unguwar Danmayaki village in Bakori Local government area of Katsina.
According to Daily Trust, Dausiya was barely two weeks into the marriage when she killed the duo with rat poison sprinkled into their food.
However, a younger sister of the deceased husband, Shafaatu Usman, 23, survived after she was rushed to hospital.
The suspect was arrested on Friday.
The Katsina Police Command confirmed the incident.