Gorakhpur, June 23 -- A 16-year-old boy was detained for allegedly hacking his elder brother, sister-in-law and their three-year-old son to death while they were asleep at their home in Uttar Pradesh's Gorakhpur district early on Monday, police said. According to police, the incident took place around 3 am in Balua village. The deceased were identified as Amit Gupta, his wife Ranjana and their son Reyansh, police said. The three victims were sleeping in the same room when the teenager allegedly attacked them with a sharp-edged weapon, police said, adding that the accused's parents were sleeping in another room at the time. Police said the boy's father heard screams and rushed to the room, where he found the three family members lying in a pool of blood. He allegedly saw his younger son coming out of the room carrying the weapon, and informed neighbours before alerting the police. Senior police officers reached the spot and launched an investigation. The teenager was detained from an upstairs room where he was allegedly found with the blood-stained weapon, police said. A case has been registered on the complaint of the victims' father, and the bodies have been sent for post-mortem examination, police said. SP (South) Dinesh Puri said, "The three victims were killed inside the room, and the juvenile is being questioned." The motive behind the killings is yet to be ascertained, police said, adding that preliminary investigation suggests a possible dispute related to a family-run shop may have triggered the incident. Further probe is underway, police said....