Police said the three were injured when a high intensity crude bomb, reportedly planted by anti-social elements beside NH2 at Lerie colony here exploded this morning.
A motor garage mechanic who was among them, was critically wounded and underwent operation at a local hospital.
Police said an explosion had taken place on Wednesday about 50 m away from today's blast site but no casualty was reported.
This is third explosion in the town this year.
No Naga underground group or individual has claimed responsibility for the blast and police are investigating the incident.