The accident occurred when the driver lost control over the vehicle early this morning, police said.
The victims were returning home after attending a religious programme in Dateli village of Sitapur district.
Police rushed to the spot and carried the injured to district hospital. One of the injured was sent to Lucknow in a serious condition for further treatment.
The deceased were identified as Abbas (60), Lal Mohammad (55) and Mehruddin (65) -- all of Bajudeeh village under the city Kotwali area, they added.