Pakistani intelligence officials say a suspected U.S. drone strike has killed five people in a Pakistani tribal region near the border with Afghanistan.

Intelligence officials say the drone fired four missiles early Wednesday on a suspected militant compound in North Waziristan.

The identities of those killed is not yet known, but the region is a stronghold of the al-Qaida linked Haqqani network.

Pakistan has repeatedly criticized drone attacks as illegal and a violation of its sovereignty, but U.S. officials say the strikes are an important tool in defeating the insurgents.

The attack comes just days after Pakistani opposition politician Imran Khan led a convoy of some 500 vehicles in an unprecedented march toward Taliban territory to protest CIA-led drone strikes.