The party also demanded chief minister Akhilesh Yadav's resignation over the incident.
The Bharatiya Janata Party (BJP) on Tuesday demanded a CBI probe into the gang-rape in Bulandshahr, Uttar Pradesh.
"The (Uttar Pradesh) government has failed to take action in the shameful and painful incident. Chief Minister Akhilesh Yadav should resign as he has failed to govern the state. Such incidents have also happened in the past," Keshav Maurya, BJP's Uttar Pradesh chief, told reporters.
"The party and the central government stand by the family. We will meet Union Home Minister (Rajnath Singh) and demand a CBI probe into the incident," he added.
Eight armed men stopped a family car on the Delhi-Kanpur highway last Saturday morning, dragged out a 38-year-old woman and her teenaged daughter and gang raped them.
The other members of the family were tied up.