The incident took place in Dallupura at around 5 pm and the deceased has been identified as Neha.
Neha and her male friend Gaurav were travelling in the latter's car when Devender (32) waylaid them.
He first stabbed Gaurav in his cheek and then stabbed Neha, who died on the spot.
Gaurav rushed to police who took her to hospital.
"Devender was arrested. He was in love with Neha.
However, she ignored him and went into a relationship with Gaurav.
This enraged him and he allegedly decided to seek revenge," a senior police official said.
