The nine-year-old girl was admitted to BR Ambedkar hospital in Rohini where her condition was stable, said a senior police officer.
The rape allegedly took place last Sunday. The accused had allegedly threatened the girl not to tell anyone about the incident. However, the matter came to light when her parents took her to hospital after she was taken ill.
A complaint was lodged at Narela police station.
The accused identified as Zakir Hussain was arrested yesterday. He taught at a madrassa in a slum of Narela, said the officer.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.