The incident happened in Banu district where an explosive-laden motorbike exploded when the vehicle of a member of a pro-government peace militia passed by it, sources from the counter-terrorism department of police told Xinhua.
The sources added that the bomb was detonated by a remote-controlled device by unknown terrorists who are being hunted in the area.
The injured people were shifted to a nearby hospital where two of them are in critical condition.
No group or individual has claimed the attack yet.
(With UNI inputs)