The incident took place this morning when the jeep was on its way to Nathusar from Khandela, they said.
The deceased were identified as Babulal (45), Chauthmal (38) and Shubham Kumar (18), they said, adding that the jeep driver Gokulchand was injured and was rushed to a government hospital in Sri Madhopur.
Although, the driver of the tractor-trolley fled the scene of crime leaving his vehicle behind, they said.
