The girl, however, survived but received critical injuries, police said.
"Narendra Kumar (25) and the girl had an affair for over one year. The girl became pregnant and was pressuring him to marry her but he was not willing for that," they said.
"Today, he took the girl to Nahargarh hills where he hit her with stones and dragged before pushing her from the hills to a gorge with intention to kill her," said the police.
Meanwhile, some travelers spotted the girl and informed police following which she was rescued and admitted to SMS Government Hospital," they said.
The accused, a vegetable vendor, has been arrested and being interrogated, said police.