The incident took place last night, when the girl was attacked by the accused youth, Biswajit Mondal (21) in Azad Hind Nagar colony. Mondal slashed her throat using a knife, a senior police officer said.
Up on hearing her scream, locals rushed to the spot and rushed the girl to nearby Panihati state general hospital.
The angry mob thrashed Mondal before handing him over to the police.
While the family of the accused claimed he was in a relationship with the victim, the girl's parents maintained she had spurned his advances and he continued to harass her.
The district had witnessed several incidents of assault on women at Kamduni, Madhyamgram, Jagaddal in recent times triggering protest by rights groups.