The 17-year-old accused is absconding, said a senior police officer.
The girl was lured by the accused on the pretext of buying her sweets, he said.
Since the accused resides in her neighbourhood, the girl went along with him. He took her to a vacant plot where he allegedly sexually assaulted her, said the officer.
Later, the girl came back home crying and narrated her ordeal to her family who made a PCR call around 12.20 PM today, he added.
"Initially, it was a blind case since we didn't have any clues of the accused. However, we scanned the CCTV footage from the area in which the accused would be seen taking the girl with him," he added.
The accused was identified and his family was questioned but it was found that they hadn't seen him after the incident, said the officer.
Police has launched a search for the juvenile and are questioning his friends, he added.