The incident took place in Sayadi village of Nahrin district on Monday night.
The district governor Mohammad Sarwar Akbari told Ariana News that the village is under the control of Taliban militants.
He added that all of the victims are children and a woman.
In a similar incident, a woman was killed and eight others including six children were injured early this week in Parwan province.
Civilians especially women and children are the most vulnerable targets to unexploded munitions scattered across the country during nearly two decades of war.