The incident took place in a busy market in Alamar district but the main target of the attack has not been ascertained so far, Al-Alam News Network reported.
In the meantime, a local security official said the suicide bomber detonated his explosives targeting the security forces around 11:45 a.m. local time.
The official further added at least 10 people were killed and over 30 others were wounded in the attack.
No group including the Taliban militants has so far claimed responsibility behind the attack.
Faryab is among the relatively volatile provinces in North of Afghanistan where anti-government armed militant groups are actively operating in a number of its districts and often carry out insurgency activities.