The deceased were identified as Snehi and Nagendra.
The incident took place late last night when Snehi, Nagendra and Shivkant were heading towards a eatery in the area on a motorbike when the dumper hit their vehicle from behind, a senior police official said.
Passers-by called up police and the three were rushed to a hospital where Snehi and Nagendra were declared dead and Shivkant was admitted with severe injuries, the official said.
A case of causing death by negligence, rash driving and causing hurt by act endangering life or personal safety of others have been registered. Efforts are on to identify the vehicle and the accused, the official said.