PESHAWAR, Pakistan â A drone suspected of being American killed at least four militants early Saturday in an attack on a compound in the North Waziristan tribal district, near the border with Afghanistan, a Pakistani security official and local residents said.  The drone fired missiles at a building and a nearby parked vehicle in a village close to Mir Ali, a notorious hub for militants from the Taliban and Al Qaeda in North Waziristan, where the majority of C.I.A. drone strikes have taken place.  The security official said the main building in the targeted compound had once been an Islamic school t run by Hafiz Gul Bahadur, the principal pro-Taliban warlord in North Waziristan, but added that it was currently occupied by militants from the Asian republic of Tajikistan.  âMilitants are clearing the rubble and pulling out the bodies,â the official said, citing local residents. âThese are preliminary reports. We do not know the identity of those killed as yet.â  It was the 18th American drone strike in the tribal belt this year, according to the London-based Bureau of Investigative Journalism, which collates data about the attacks. The strikes have drawn fierce criticism from Pakistani officials, with the countryâs new prime minister, Nawaz Sharif, demanding that the United States end such attacks.  The last strike occurred on July 28, when a missile struck a group of militants near the Afghan border. As is typical, details of that strike were blurry. Between five and eight people were killed then, according to reports, some of which said the fighters had gathered for an evening meal while others said they had just crossed into Pakistan from Afghanistan.  There have been over 370 American drone strikes in Pakistan since the covert C.I.A.-directed campaign started in 2004.  Ihsanullah Tipu Mehsud contributed reporting from Islamabad, Pakistan, and Declan Walsh from London.
The strike, believed to have been carried out by the United States, took aim at a hub of militancy along the Afghan-Pakistani border.