Islamabad, Pakistan (CNN) -- A suspected U.S. drone strike targeted a militant compound in northwest Pakistan Thursday, killing at least four people, two Pakistani intelligence officials said.
The officials, who spoke on condition of anonymity, said the drone fired two missiles at the compound near the village of Mir Ali in North Waziristan, one of seven districts in Pakistan's volatile tribal region bordering Afghanistan.
North Waziristan is known as a militant hub and has been targeted frequently by suspected U.S. drone strikes for years.
Those targeted in the drone strike were militants, the officials said.
It's the second strike in as many days in the district.
Many residents of the region say the strikes have killed dozens of civilians, including children and women. U.S. officials say the drone strikes are an effective strategy against militant groups and insist civilian casualties are rare.
CNN's Nasir Habib contributed to this report.