A US drone fired two missiles into a compound in northwest Pakistan early Friday killing at least six militants, officials said.

The attack took place in Dargah Mandi, about 10 kilometres (six miles) from Miranshah, the main town in North Waziristan tribal district, along the Afghan border.

"It was a US drone strike. Six militants were killed, the death toll may rise," one security official in Miranshah told AFP.

A second security official in Peshawar, the regional capital, confirmed the attack and death toll.

The area where the drone strike hit is a stronghold of the Al-Qaeda-linked Haqqani network. The official in Miranshah told AFP that all those killed were Haqqani fighters.

The official in Peshawar said the identities of those killed was not yet clear.

US drone attacks are deeply unpopular in Pakistan, but Washington views them as a vital tool in the fight against Taliban and Al-Qaeda militants in the lawless tribal areas along the border with Afghanistan.

The Pakistani government has repeatedly protested against drone strikes as a violation of its sovereignty and there has been a decrease in their use.

During a visit to Islamabad at the start of August, US Secretary of State John Kerry suggested that drone strikes targeting Taliban and Al-Qaeda operatives in Pakistan could end "very soon" as the threat of militancy recedes.