The Rashtriya Janata Dal said that Bihar Chief Minister Nitish Kumar should resign taking moral responsibility for the alleged sexual exploitation of girls at a state-run shelter home in Muzaffarpur as he also holds the home portfolio.
Leader of Opposition Tejashwi Yadav asked why the state government is not ordering a CBI probe into the case.
Mr Kumar should resign for the "overall rise in crimes against women", the RJD leader told reporters and reiterated the party's demand for CBI inquiry into the shelter home rapes.
The CBI probe should be monitored by the high court, Mr Yadav, who led a delegation of the opposition RJD, Congress, Hindustani Awam Morcha (HAM) and CPI-ML, said.
"We wonder why the state government is not ordering a CBI inquiry despite the statement given by Union Home Minister Rajnath Singh yesterday... We stick to our demand for a CBI inquiry, notwithstanding unconvincing arguments against it by the government put through officials like the DGP. We demand that the probe be monitored by the High Court," Mr Yadav said.
Bihar Director General of Police KS Dwivedi had said on Tuesday that medical examinations of 29 of the 42 inmates confirmed that they were sexually exploited and that 10 of the accused have already been arrested while efforts were on to arrest an absconding one.
Mr Yadav claimed that some leaders of the ruling NDA in Bihar are trying to influence the investigation into the Muzaffarpur shelter home rapes.
"During our visit we have met a cross-section of people who have told us that some leaders sitting in New Delhi and Patna were calling up officials in the administration here with a view to influencing the investigation in the case," the leader of the opposition said.
"We have been saying that the ruling government in the state is trying to shield the accused, many of whom are close to people in power," he said.
Mr Yadav claimed that Brajesh Thakur, who is the patron of the NGO which ran the shelter home, had been a part of Mr Kumar's campaign team in Muzaffarpur during the last Lok Sabha elections.
Upon his arrest, he was alleged not to have cooperated with the investigation and yet his police remand has not been sought, Mr Yadav said.
"Although the shelter home housed little girls, we have learnt that tools used in abortion were kept here. This aspect has not been examined either," he said.
"It is clear that the state government has neither the competence nor the intention to carry out a fair and impartial investigation," he alleged.
The RJD will hold a state-wide cycle rally against the rise in the incidence of crimes against women, specially young girls, in Bihar beginning later this week with the slogan 'NDA Bhagao Beti Bachao', he added.
Echoing Mr Yadav on the demand for a CBI probe into the scandal, HAM chief and former chief minister Jitan Ram Manjhi said the government took a month to act on the social audit report on the shelter home and its officials and several more days to file an FIR.
He asked whether the delay was intended to enable the culprits to tamper with evidence.
Other members of the opposition team were Sadanand Singh of Congress and Mahboob Alam of CPI-ML.
Follow NDTV for latest election news and live coverage of assembly elections 2019 in Maharashtra and Haryana.
Subscribe to our YouTube channel, like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.