Pakistan's tribal regions close to the Afghan border are seen as strongholds of anti-government fighters linked to the al-Qaeda and Taliban.
 
'US missile'

A security official said he believed the missile was fired by US forces, who are operating in Afghanistan.

The house that was hit belonged to Sher Mohammad Malikkheil, a Pashtun tribesman with known links to fighters in the area.

The US military have fired missiles on the Pakistani side of the border several times in recent years, most recently in late January when Abu Laith al-Libi, one of Osama bin Laden's top lieutenants, was killed.

That missile was believed to have been fired by a US pilotless drone.

However, neither US nor Pakistani authorities officially confirm US missile attacks on Pakistani territory,

It can be considered an infringement of Pakistani sovereignty.