"We have arrested the driver Santosh Sahu and conductor Bibhuti Rout of Athagarh and recovered the weapon of offence - a wrench," Amresh Panigrahi, Sub-Divisional police officer (SDPO) of Banki said.
He said the police scientific team have also recovered some blood-stained apparels from the bus, which have been sent for examination.
The body of the girl has been recovered below Jatamundia Bridge over river Mahanadi on the outskirts of Banki on Wednesday morning with a deep wound on her forehead, police said.
Quoting family sources, police said the girl had left her home on August 1 in the morning saying she was going to a relative's house nearby and did not return.
Interrogating the accused, it was found that the girl was reportedly taken in the bus to a desolate place in Ratagarh, where she was gangraped before being murdered.
Not ruling out the involvement of more persons in the crime, police said the girl apparently died instantly when her forehead was hit severely with the wrench.
