ISLAMABAD, Pakistan — A leader of the militant Haqqani network and two of his aides were killed Wednesday in an American drone strike in northwestern Pakistan, an attack that was denounced by the Pakistani government.

The attack took place on Wednesday morning in the Speen Thal Dapa Mamozai area of the Kurram tribal region and was directed at a house that the Pakistani authorities said was being used by Afghan refugees. The militant commander, Nasir Mehmood, who was also known as Khawari, and two of his aides were killed.

The Haqqani network, affiliated with the Taliban and designated as a terrorist group by the United States, has carried out numerous deadly attacks in Afghanistan in recent years. The presence of its leaders and militants in Pakistan and its links with the country’s military intelligence agency have long caused friction between United States and Pakistan.

The Kurram region has been used frequently by Haqqani network fighters to cross into neighboring Afghanistan.