The deceased lived with her family on a footpath, police said.
According to police, the victim's parents found her missing when they woke up in the morning, after which they started searching for her.
Her body was found 100 ft away from their hut among plants near the footpath at around 6:30 am, they said.
Locals informed the police who rushed the girl to Nair hospital where she was declared dead on arrival.
"Medical reports have confirmed that the victim was raped and strangulated to death. A case has been registered in this regard," police inspector Sushil Ingale of Worli police station said.
A few persons have been detained and other slum dwellers are being questioned, he said.
The victim's father is a crane driver and mother does odd jobs.
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