The riflemen of 2/11 Gorkha Rifles died in the mishap which occurred when they were shifting ammunition from Sanu area to Ramgarh area, police said.
"Prima facie, it seems the driver lost control over the vehicle during an overtaking bid," a policeman, Devi Singh, present at the spot, told PTI.
Two persons died on the spot and three succumbed to injuries at a hospital, he said.
The injured were taken to Jodhpur in an IAF helicopter, he said.
Defence spokesperson Col S D Goswamy said a court of inquiry has been ordered to ascertain facts.