Babar Jang, the brother-in-law of the victims, was arrested along with one Javed from Kandhla town of the district, Shamli SP Abdul Hameed said in a press conference.
During interrogation, they disclosed that they had hired two persons for the purpose, Hameed said, adding efforts are on to arrest them.
The sisters -- Kamerjahan (26), Ayisha (25), Isha (23) and Sanam (20) -- were attacked on April 2 when they were returning from a local college after board examination duty.