A seven-year-old boy was allegedly sodomised and set on fire by two unidentified youth at Padmanagar in Bhiwandi town in the district, police said on Sunday.
The incident took place on Saturday when the victim had gone to eat at 'a langhar', inspector RS Sasthe said.
The accused took the boy to an isolated place and sodomised him, and when he resisted, they set him on fire, the officer said.
The boy, who suffered 30% burn injuries, somehow managed to escape, Sasthe said.
A case has been registered under sections 307 (attempt to murder), 377 (sodomy) of the Indian Penal Code and relevant sections of Protection of Children from Sexual Offences Act, 2012.
The boy is being treated at the Thane Civil hospital. Efforts are on to identify and nab the accused, the inspector said.