The four were arrested from the Purani Para Police Chowki area under the Para Police station in Lucknow on Tuesday. Several documents and fake certificates and a mobile phone were also recovered from them.
The incident occurred around 10.15 pm on Tuesday in Swaraswati enclave of Sector 10 when the deceased was walking towards his house after parking his taxi.
"It is disturbing to see the baseless and malicious allegations that are being made. Politics on a sensitive crime is not a good sign for our democracy," CM Patnaik said.
Rajasthan Chief Minister Ashok Gehlot attacked Union Minister Gajendra Singh Shekhawat and said that the latter's crime has been proved in Special Operations Group (SOG) investigation in 'Sanjeevani Cooperative Society scam.
The shocking incident took place at Brijnagar under Tikrapara police station limits this evening, Tikrapara Station House officer (SHO) Amit Beriya said.
According to police, the incident took place on Monday, when the accused, former student, Ashutosh Srivastava, poured petrol on the 49-year-old principal and then set her ablaze.
"The incident was an organised crime, which happened after a spur between two groups. But the police took immediate action on the incident and arrested the culprits," said the minister.
Sahil further claimed that he had decided to push Nikki out of the car. However the plan could not be executed and he killed Nikki at Nigambodh Ghat, the police sources added.
In a sensational revelation in the Nikki Yadav murder case, the Delhi Police sources on Monday said that accused Sahil Gehlot's father Virender had been arrested in a murder case earlier.