Police said that the girl, a resident of Padavedu near Arani and a student of the government higher secondary school at Rengukondapuram, was daily accosted by Pasupathy (21), son of Murugan of Mangalapuram.
He used to follow the girl while going to and returning from the school, every day. The youth proposed to his love to her and insisted to accept it.
Even after repeated requests, the girl refused to accept his proposal.
On Friday also, he confronted the girl with the same request, but she stood firm in her decision. Angered by this, the youth pulled out a knife and repeatedly stabbed the girl, who fell on the road with injuries.
Locals, who came to the rescue of the girl, thrashed the youth before handing him over to Sandavasal police.
A case of attempt to murder was registered against the youth, who was subsequently remanded to custody.
The girl has been admitted to the Vellore government medical college hospital, where her condition was said to be progressing. Investigations are under way.