An investigation has been launched into the incident, the police said. (Representational)

A 17-year-old boy was arrested for allegedly sexually assaulting a five-year-old girl in Machilipatnam town in Krishna district of Andhra Pradesh on Saturday, the police said.

The accused is a neighbour of the child, the added.

"We received a complaint from the girl's parents that the boy... had molested her. Accordingly, we registered a case against the teenager, who is a student in the local college," the Station House Officer said.

The child was admitted to a government hospital for treatment and her condition is said to be stable, the police said.

An investigation has been launched into the incident, the police said.