The 12-year-old girl forcibly taken away by the four accused from Howly and was allegedly gangraped inside a house near Barpeta Medical College and Hospital yesterday, police said.
The boys, after allegedly raping her, fled from the house and left the girl alone after threatening her not to tell the police, they said.
The girl's parents filed an FIR at Howly police station and her medical test was done today.
Earlier, another minor girl was allegedly gangraped inside a moving bus by its driver and assistant at Goreswar in Baska district on Sunday.
The victim had filed a case yesterday and the accused were yet to be arrested, the police said.