An ambulance van, which was part of 108 Emergency Response Services, dashed into an autorickshaw coming from opposite direction at Aishwarya Garden on the city's outskirts around midnight on Friday.
Three persons travelling in the autorickshaw were killed and two others injured, police said.
Two of the victims died on way to Mahatma Gandhi Memorial (MGM) Hospital, while the third one breathed his last during treatment, police said.
The deceased were identified as Pasha Miya, P Rajesh and Ailaiah. The injured are undergoing treatment in MGM Hospital, police added.