The incident took place last night, Kotwali In-charge Babban Yadav said, adding, the victims, belonging to Ghungarpur village were coming from Tulsipur side.
The jeep overturned and fell in a roadside ditch after being hit by the truck, Yadav said.
Those killed have been identified as Babadeen (18), Omkar (17), Kushal (17), Goli (18), Aslam (18), and Lalchand, he said.
Two of the three injured are in critical state and have been referred to Gonda hospital while one other was admitted to the district hospital here.