Provincial governor’s spokesman Ataullah Khogyani confirmed the incident has taken place in the vicinity of the 6th police district of the city.
He did not disclose further information and there are no reports available regarding the type of the explosion.
However, a security official said a suicide bomber detonated his explosives near a security post, leaving at least two dead and two others wounded.
The source further added that a security soldier and a civilian are among those killed.
However, the provincial government media office in a statement said at least two NDS operatives lost their lives in a suicide attack and at least four others including a civilian and three security personnel sustained injuries.
No individual or group has so far claimed responsibility behind the incident.