The brutal murder triggered a deluge of reactions on social media with hashtags demanding just for the girl trending on Twitter.
The Gandhi siblings too joined the chorus and tweeted on the case demanding stringent punishment for the culprits.
"The horrific murder of a little girl in Aligarh UP has shocked and disturbed me. How can any human being treat a child with such brutality? This terrible crime must not go unpunished. The UP police must act swiftly to bring the killers to justice," tweeted Rahul Gandhi.
"The brutal murder in Aligarh is yet another inhuman, unspeakable crime against an innocent child. I cannot even begin to imagine the pain her parents must feel. What has become of us?" Priyanka Gandhi wrote on the micro-blogging website.
The body of the girl was found in a garbage dump on Sunday.
Two persons, Zahid and Aslam, have been arrested for killing the child in Tappal area of the city.
Police said on June 5 that the girl was abducted and killed in a revenge crime over a financial dispute her father had with Zahid.
A postmortem was conducted under the supervision of a three-doctor team which confirmed that she was strangulated but ruled out the possibility of rape, the police said.
Aligarh Police have decided to probe the National Security Act (NSA). Speaking to ANI on Thursday, Aligarh Senior Superintendent of Police (SSP) Akash Kulhary had said they will try to transfer the case to a fast track court.