Police arrested the key accused of gang-rape of two sisters from Torabganj bazaar in Kamalnagar upazila of Laxmipur district on Sunday midnight.Two separate cases were filed in the incident of two sister’s rape.Confirming the matter, Kabir Ahmed, officer-in-charge (OC) of Kamalnagar Police Station said one kokhon was main accused of one of the cases.Two sisters were picked up by a gang of culprits from their house and gang-raped in an abandoned house on March 29.