US drones fired off a volley of missiles targeting Al Qaeda-linked fighters in a tribal area of northwest Pakistan on Wednesday, killing at least 11 militants, security officials said.

The pre-dawn attack — the third in less than 24 hours — was directed at the Haqqani network, a Pakistan-based group that is one of the toughest foes for foreign forces in the war in neighbouring Afghanistan.

"Several US drones fired seven missiles at two militant compounds early this morning, killing at least 11 militants," a senior security official told AFP. "The missile strike targeted militants of the Haqqani network."

The attack took place in the village of Dargah Mandi village on the outskirts of Miranshah, the main town in the troubled North Waziristan tribal district where US missiles killed 15 militants in two separate attacks Tuesday.

Another security official in Peshawar and a local intelligence official confirmed Wednesday's strike and the death toll. "They were Pakistani Taliban attached to the Haqqani group," the intelligence official in Miranshah said.

Created by Afghan warlord Jalaluddin Haqqani and run by his son Sirajuddin, the network is linked to both Al Qaeda and the Taliban and has become a particularly prickly thorn in the side of US-led forces trying to bring security to eastern Afghanistan.

Residents said the targeted houses were owned by local tribesman Bacha Khan, who had rented them out to militants, and were destroyed in the attacks, which caused panic in the village.

"As the US drones came over the village people started shouting and running here and there shouting ‘run, drones have come’, a local tribesman told AFP, requesting anonymity for fear militants might harm him.

A fresh surge in US missile strikes has killed 75 militants since September 3 in Pakistan's northwestern tribal belt, which Washington has branded a global headquarters of Al Qaeda and the most dangerous spot on Earth.

On Tuesday, 11 militants were killed in a drone attack on the village of Bushnarai in Shawal district, a known stronghold of Taliban warlord Hafiz Gul Bahadur that is populated by Arab fighters.

Another four were killed in Qutabkhel village south of Miranshah when US drones fired missiles on militant vehicles, officials said.

With Pakistan struggling to cope with devastating floods that have hit 21 million people in the country’s worst humanitarian disaster, Islamist militant violence has picked up in recent weeks with a wave of major bombings.

The Taliban last week threatened Pakistani security forces with more suicide attacks to avenge US missile strikes, which have become a key tactic in the US-led fight to reverse the Taliban insurgency in Afghanistan.

An Islamist militant bombing campaign has killed more than 3,700 people and fanned instability across nuclear-armed Pakistan since July 2007.

Under US pressure to crack down on Islamist havens along the Afghan border, Pakistan has in the past year stepped up military operations against largely homegrown militants in the area.

Officials in Washington say the drone strikes have killed a number of high-value targets including Pakistani Taliban chief Baitullah Mehsud and help protect foreign troops in Afghanistan from attacks plotted across the border.

The US military does not as a rule confirm drone attacks, but its armed forces and the Central Intelligence Agency operating in Afghanistan are the only forces that deploy pilotless drones in the region.

Over 1,080 people have been killed in scores of drone strikes in Pakistan since August 2008, including a number of senior militants. However, the attacks fuel anti-American sentiment in the conservative Muslim country.

Former Pakistan President Pervez Musharraf, who is planning a return to the frontline of the country's political scene, spoke out against the attacks during a visit to Hong Kong on Wednesday.

"It is a violation (of Pakistan's sovereignty)... The sensitivity of the people of Pakistan is that no outside force should cross (its) border," he told reporters.

Al Qaeda announced in June that its number three leader and Osama bin Laden's one-time treasurer Mustafa Abu al-Yazid had been killed in what security officials said appeared to be a drone strike in North Waziristan.