The accused Shaikh Hasan Shaikh Hussain (40), a resident of Hari File area, waylaid the class V student on her way to attend nature's call yesterday, they said.
Hussain allegedly took the girl to an isolated spot and sexually assaulted her after offering her a Rs 20 note, police said, adding he dumped her at Jiya Colony after committing the crime.
Following a complaint lodged by the girl's family, police registered an FIR under section 376 (2)(f) (committing rape on a woman when she is under twelve years of age) of the Indian Penal Code (IPC) against Hussain and arrested him.
In another incident, an unidentified person molested a five-year-old girl at Lohgad village after luring her with chocolate on December 25.
A complaint in this regard was lodged by the victim's mother on December 29, police said.
In a similar incident, a nine-year-old girl was molested in Ural village by an unidentified person, police said, adding the search is on to trace the accused.