The three victims, who were killed when a suspected suicide bomber targeted a security convoy in the restive area, were US soldiers.
When rediff.com contacted a security official, he confirmed, "There were three US soldiers among the victims. They were in the area to train the (paramilitary) Frontier Corps."
Dir district is considered to be the geographical link between Taliban militants in the districts of Swat and Bajuar in Pakistan and Nuristan and Kunar in Afghanistan.
The Taliban started its rampage in Swat region in early 2007 when they started attacking Pakistani soldiers, killing policemen and destroying local schools.
But the Taliban militants, led by Maulana Fazlullah, refrained from crossing over to Afghanistan and fighting the North Atlantic Treaty Organisation's forces.
As the Taliban strengthened its presence in Lower Dir, which is located between Swat district and Bajuar Agency, they helped the Taliban unit in Swat establish a link with the Tehrik-e-Taliban Pakistan in the Federally Administered Tribal Area, FATA.
Helped by Taliban militants in Pakistan, the fundamentalist outfit slowly established its presence in Kunar and Nuristan, under the leadership of Qari Zia-ur-Rehman, who is suspected of having close links with Al Qaeda.
Under pressure from the United States, Pakistan launched an offensive to flush out Taliban militants from Swat in May 2009.
The militants of Swat enjoyed close ties with Zia-ur-Rehman, and many of them fled to the areas controlled by him across the border to escape the offensive. Taliban leader Maulana Fazlullah is suspected to be hiding in Nuristan.
But the mass migration of militants to Afghanistan's border districts did not bode well for the US. The resurrected Taliban in Afghanistan, bolstered by the presence of the Swat militants, renewed their attacks against NATO forces.
Worried by the surge in the attacks against the NATO-led forces in Afghanistan, the US has decided to monitor the situation in Pakistan's Dir and Swat regions closely. The three American soldiers killed in Wednesday's suicide attack may have been in the area for that purpose.