Pakistani security officials said the suicide bomber blew himself while targeting a vehicle of Afghan border forces close to a check post in the Chaman region near the Friendship Gate at Pak-Afghan border.
"Some of our forces were also injured in the blast," they said.
Security sources in Quetta said that five Afghan border officials were killed in the blast apart from the Afghan border commander, Akhtar Muhammad.
He confirmed that Afghan border commander Muhammad had also been killed in the explosion.
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Afghan security officials said Muhammad was the intended target of the suicide attack.
"Initial information is that the suicide bomber walked from the Pakistan side of the border to the border friendship gate where he targeted a vehicle of Afghan officials," one source said.
The condition of five of the injured persons was stated to be serious and they were rushed to the border town of Chaman for medical treatment.
Pak-Afghan border was immediately closed after the blast.
Later, Frontier Corps personnel were called at the border to control the situation.
Security was tightened on both sides of the border to avert other untoward incidents.
Chaman is a small town in the southwestern province of Balochistan and is one of the two main crossing points for supplies for American and Nato troops fighting the Taliban in Afghanistan.
Balochistan, which borders Iran and Afghanistan, suffers from a local separatist insurgency.