Akash, 17, was stabbed near his house Friday evening by two other teenagers from his locality in Mangolpuri in north Delhi, said a police officer Saturday.
The boy was taken to a hospital but declared brought dead.
The two attackers have been arrested and sent them to a juvenile home.
Akash had molested a sister of one of the teens and in a fit to rage, they stabbed him, said the police officer.
Photos: Parineeti Chopra's night out with friends in Bandra
Spotted: Kriti Sanon at spa in Juhu
'Look' how the Sheena Bora case has taken a toll on Indrani Mukerjea
Photos: Katrina Kaif, Parineeti Chopra, Shilpa Shetty's movie outing in Juhu
Birthday special: 14 Bollywood actors who made it big on TV