A 12-year-old girl found burnt at an under-construction building in Gondwana Nagar in Nagpur, succumbed to her injuries on Saturday, police said.
The minor was last seen with a youth from her locality before she went missing on Thursday, they said.
Police said they were alerted by a neighbour of the girl when he saw her on fire and screaming at the spot on Friday.
She was rushed to Government Medical College hospital where doctors said she had sustained 90% burn injuries.
"The girl died in the wee hours today (Saturday)," police said.
They were exploring possibilities like rape, suicide and kidnapping as probable reasons behind the incident. They are also awaiting the post-mortem report.
After initially registering offence for kidnapping under relevant sections of the IPC, police today added the charge of murder against unknown person(s).