The sadhvis, who were sisters, were gangraped by the ashram in-charge Swami Aryanand and his associates in a field inside the premises on Sunday night.
The accused were identified as Aryanand, Ghanshyam Mandal, Vivekanand Sinha, Pankaj Kumar, Prem Yadav, Ratna Paswan and three other unidentified persons, police said.
A case has been registered against various sections of IPC but no one has been arrested, they added.
The sadhvis from Katihar district, have been staying at the ashram for some time, the sources said.
