A man sustained critical injuries after an explosion in an auto-rickshaw which he was driving on Tankapani Road under the Badagada police station in the city on Sunday evening.
The victim Govinda Rao was admitted to a private hospital for treatment.
The incident reportedly took place at around 8 pm. There were no passengers in the vehicle.
On being informed, the Badagada police reached the spot and began a probe into the incident. Sources said police have found remnants of crude bombs at the spot.
It was suspected that bombs exploded inside the three-wheeler.
Police were trying to ascertain whether someone had kept the explosives deliberately in the vehicle or the driver was carrying them.