Provincial police spokesman Zia Durani said the incident took place earlier today on a main highway connecting Spin Boldak and Arghistan district.
He said a rickshaw vehicle carrying civilians struck an Improvised Explosive Device (IED), leaving at least three children dead.
Durani further added that six others including three women and three men also sustained injuries in the attack.
No group including the Taliban militants has so far claimed responsibility behind the incident.
The Taliban insurgents and militants belonging to the other insurgent groups are frequently using Improvised Explosive Device (IED) as the weapon of their choice to target the security forces.
The IEDs are the main contributors to the casualties of the Afghan security forces but are also considered as a key factor in growing civilian casualties.
At least 11 civilians belonging to a same family were killed in a similar attack in northern Baghlan province of Afghanistan late in the month of May.
At least 600 civilians were killed and 1,343 others were wounded in the first quarter of 2016, the United Nations Assistance Mission in Afghanistan said in its latest report.
UNAMA further added that consistent with 2015 trends, ground engagements caused the highest number of total civilian casualties, followed by improvised explosive devices (IEDs), complex and suicide attacks, as well as targeted killings.
According to UNAMA, actions by Anti-Government Elements caused at least 60 per cent of casualties while Pro-Government Forces caused at least 19 per cent.