Twenty persons were killed and 20 others were injured when a suicide bomber riding a motorbike blew himself up in the border town of Spin Boldak on Monday. Some police officers, too, were injured in the incident.
The incident also set ablaze three vehicles in the area.
The blast, that took place in a busy market where locals were watching a wrestling match, occurred hours after a suspected Taliban suicide car bombing in Kandahar killed three soldiers and a civilian.
The Afghanistan Government accused Pakistan of failing to crack down on militants along the long, porous border.
"There are training camps of extremists and terrorists on the other side of the border who train and equip the terrorists in order to launch terrorist attacks in Afghanistan," an official said.
The attacks are the latest in a wave of more than 20 suicide bombings that have struck Afghanistan recently, mostly aimed at US-led forces and their NATO allies, but also at Afghan forces and civilians.