Police said the minor's naked body was found stuffed in a jute bag and dumped in the New Usmanpur area.
Police said it will wait for a post-mortem to ascertain whether the 11-year-old was a victim of sexual assault.
The girl, a student of Class 5, was a resident of Gautampuri and had gone to a nearby shop on Tuesday afternoon to buy grocery.
After she failed to return home, her father registered a missing complaint at the New Usmanpur Police Station, a senior police officer said.
"Her body was found on Wednesday morning when some locals found a jute bag dumped in a street. A case under Section-302 (murder) of the Indian Penal Code has been registered," Deputy Commissioner of Police (North-East) Ajit Kumar Singla told IANS.
