The incident took place at Dandipada village in Palghar district in the wee hours.
"The accused entered the victims' house between 3 am and 4 am, and lifted the minor girl and her brother, who were asleep with their parents. They took the siblings to a nearby place and raped the girl," Manoj Landge, spokesperson of Palghar district police said.
"The accused also injured her one-year-old brother behind his ear and on his private parts. The child was later hospitalised and is currently undergoing treatment," he added.
The accused have been booked under IPC sections 307 (attempt to murder), 376 (2)(i) (rape), 326 (voluntarily causing grievous hurt by dangerous weapons or means) and also sections of Protection of Children from Sexual Offences (POCSO) Act, 2012, police said.