The deceased, identified as Chandrika Prasad Yadav, 68, Kapil Dev Yadav ,33, and Suresh Chandra Yadav, 38, died on the spot in the accident that took place late on Tuesday night.
Superintendent of Police (SP) Aakash Tomar said Jai Prakash Yadav ,22, and Anugraha Narayan Yadav ,32, were seriously injured and have been admitted to a hospital in Prayagraj.
All the victims belong to Sarai Mamrej police station area in Prayagraj.
The SP said that the truck driver fled leaving the vehicle behind.
The bodies have been sent for post-mortem, he added.
