According to district magistrate G S Priyadarshi, the three accused Shehzad, Kadir and Yasin, who are already in jail, have been booked under the NSA yesterday in connection with the case.
Last month, another accused Israr was booked under the stringent act. He was also in jail.
On June 5, a clash broke out between two groups due to an overflowing drain at Nasirpur village. One person, identified as 22-year-old Akash, was killed due to bullet injuries and six others, including his father, were injured, the police had said.