Pakistani security officials say a U.S. drone attack targeting a militant compound in northwest Pakistan has killed at least four militants.
The officials spoke on condition of anonymity.
Two other militants were wounded in the attack in the Shawal area of South Waziristan tribal region, bordering Afghanistan.
The area is considered to be a hub of the Taliban and Al-Qaeda activity.
The attack came despite Islamabad's demands to halt such air strikes.
Pakistan says such attacks violate its sovereignty.
Unintended casualties in the attacks have also caused tensions.
Based on reporting by AFP and AP