Provincial governor spokesman Jawed Faisal confirming the report said the incident took place while a vehicle of the Afghan police forces was crossing the area.
Mr. Faisal further added, at least 2 Afghan police officers and an Afghan civilian were killed and five other police officers were injured.
He said the explosion took place after a suicide bomber detonated explosives packed in a motorcycle near the vehicle of the Afghan police forces in Mirwais Meena area of southern Kandahar city.
No group including the Taliban militants has so far claimed responsibility behind the incident.
In the meantime unknown gunmen on Wednesday afternoon shot dead two Afghan national police officers and an Afghan civilian in Lashkargah city of southern Helmand province.
Helmand provincial governor spokesman Daud Ahmadi said the incident took place around 8:30 pm local time in the central city of Lashkargah.