Eight policemen have so far been suspended in connection with the case.
Speaking to ANI, Yadav alleged that the Chief Minister is not concerned about the implementation of liquor ban in Bihar.
"In Bihar, liquor ban is only on papers. Nitish Kumar is not bothered about its implementation and had imposed a complete ban for political benefit," he said.
Yadav added, "In reality, there is no ban as such in Bihar. The only change that took place is that now liquor is being sold at a higher price."
He asserted that Bihar's condition is deteriorating and blamed Kumar for this failure.
"Everywhere people are dying after consuming spurious liquor. The law and order has become worst. There is mafia raj in Bihar today... This is Nitish Kumar's failure," he said.
At least five people were killed and four others were stated to be critical after consuming illicit liquor in Danwar village of Bihar's Rohtas district.
Shahabad Deputy Inspector General of Police Mohd Rehman confirmed the incident and suspended the Station House Officer (SHO).
Rehman said that strict action will also be taken against the excise department.
The DIG along with the District Magistrate and the Superintendent of Police reached the spot to take stock of the situation.
On 26 November 2015, Bihar Chief Minister Nitish Kumar had announced that alcohol would be banned in the state from 1 April, 2016.