The incident took place at Kambosani village on the Vadali-Dharoi road today morning.
According to Vadali police sub-inspector K R Parmar, the driver of the jeep, which was hired by these passengers, fled the spot after causing the accident.
The deceased have been identified as Jenusinh Chauhan, Arvindsinh Chauhan and Ranjanben Chauhan, all residents of Himmatnagar in Sabarkantha district, he said.
Police investigation revealed that six members of the Chauhan family boarded the jeep from Himmatnagar to reach Piplodi village to attend a marriage function.
Before the driver could react, the speeding vehicle hit the wild animal and overturned, killing three on the spot, the police official said.
"After causing the accident, the unidentified driver fled the spot. We have admitted the three injured passengers to a nearby hospital and started further investigations after lodging a case of rash driving against the driver," Parmar said.