A suspected U.S. drone strike has killed at least three people in Pakistan's restive North Waziristan tribal region Sunday.

Pakistani intelligence officials said two missiles fired from an un-manned American aircraft struck a militant compound near the region's main town of Miran Shah.

Miran Shah, located along the border with Afghanistan, is a known refuge for al-Qaida and Taliban-linked militants.

The attack came as the world observed the 10th anniversary of the September 11 terror attacks against the United States.

U.S. officials do not publicly acknowledge the use of drone strikes inside Pakistan, but privately have confirmed their existence to various news outlets. Pakistani leaders condemn the strikes as a violation of the country's sovereignty.