A case has been registered based on a complaint by the girl's father.
Miffed over not accepting his friend request on social media, a teenager allegedly killed a 16-year-old girl and injured her mother, police said on Monday.
Accused Ravi is a resident of Muzaffanagar, Superintendent of Police (city) Martand Prakash Singh said.
A case has been registered based on a complaint by the girl's father Tejveer Singh, a security personnel at a Faridabad factory, Station House Officer Ajay Kaushal said.
The incident took place in Nagla Bohra village under Highway police station limits late on Sunday when Ravi came over to their house with a wedding card.
As the girl walked towards Ravi to collect it, he allegedly stabbed her, the SP said. When her mother Sunita came to rescue her, he attacked her as well, the officer added.
Later, he tried to kill himself with the knife, the SP said.
In his complaint, Tejveer alleged that Ravi killed his daughter as she did not accept his friend request on Facebook.
Sunita and Ravi are undergoing treatment, Circle Officer Dharmendra Chauhan said.