The body of a local journalist Raman Kashyap, who had been missing after Sunday's violence, was found in the mortuary on Monday, taking the death toll to nine, including four farmers.
The Samyukta Kisan Morcha claimed that Ashish Misra's vehicle ran over farmers who were protesting against Uttar Pardesh Deputy Chief Minister Keshav Prasad Maurya's visit to a village in Lakhimpur Kheri.
Ajay Misra and his son Ashish, however, claimed that protesters attacked the convoy and killed a driver and three others, including two BJP workers.
Congress leader Priyanka Gandhi Vadra, who went to meet the affected families in Tikunia, was detained by the Uttar Pradesh Police in the Hargaon police station area.
Uttar Pradesh Chief Minister Yogi Adityanath said strict action would be taken against those found guilty.
Meanwhile, the farmers, on Monday morning submitted a charter of demands to the District Magistrate Arvind Kumar Chaurasia, that included dismissal of Union Minister Ajay Mishra Teni, registering an FIR against his son Ashish Mishra, compensation for the families of the deceased and a government job for the kin.
The farmers have also demanded a judicial probe into the incident.
The district magistrate said that he had forwarded the charter of demands to the government and a decision would be taken soon.
Internet services in Lakhimpur and adjoining districts remained suspended on Monday.