Pakistani security officials said a suspected U.S. drone (unmanned) aircraft has fired missiles at a site in the tribal region of northwestern Pakistan.

Officials said the missiles struck a compound Saturday in South Waziristan, near the Afghan border, killing at least eight people.

Their identities were not immediately known.

The region is seen as a stronghold of al-Qaida and Pakistani Taliban militants.

Suspected U.S. drones have carried out at least 30 missile strikes on militant targets in northwest Pakistan over the past year.

The United States rarely discusses the strikes, which Pakistan has criticized as counterproductive and a violation of its sovereignty.

The latest missile attack comes as Pakistani security forces are battling extremist militants elsewhere in northwestern Pakistan, around the Swat valley.

Some information for this report was provided by AP.