The incident took place in central city of Qalat at southern Zabul province and there are fears of heavy casualties following the blast.
Provincial security chief Ghulamn Jilani confirming the report said coordinated blasts took place near the Zabul municipality department.
Mr. Jilani further added the incident took place while a vehicle of a priviate security company was crossing the area injuring at least three security guards.
He said the explosive device was planted inside a garbage container.
In the meantime provincial governor spokesman Mohammad Sharif Nasiri said the second explosion took place 15 minutes after the first blast killing at least two people.
No group including the Taliban militants has so far claimed responsibility behind the incident.