The mishap took place as the speeding truck lost control and hit several road users, Town police station's Station House Officer (SHO) Prakash Singh said, adding that eight people sustained injuries.
The tractor first knocked down two motorcyclists before hitting six other persons, he said, adding the injured were admitted to the Sadar hospital for treatment.
The tractor has been seized and the driver arrested, Singh said.
The irate local people blocked NH-83 near Arwal road for one hour to protest against against the incident.