A US drone strike on Monday killed at least 12 people in Pakistan's northwestern tribal belt near the Afghan border, security officials said.

The strike hit the Dandey Darpa Khel area, about five kilometres (three miles) from Miranshah, the main town in North Waziristan district, a known hub for Taliban and Al-Qaeda linked militants.

The area is also famous as stronghold of the Al-Qaeda-linked Haqqani network, known for staging attacks on US and NATO troops fighting in Afghanistan.

"The latest reports said at least 12 people have been killed in this drone attack, there were five militants among the dead," a security official in Peshawar told AFP by telephone.

Another senior security official in Peshawar earlier told AFP that the US drone had fired three missiles, hitting a house used by militants.

An intelligence official in Miranshah also confirmed the attack and the toll.

Officials said they were trying to confirm reports that seven civilians were among the dead, as the strike badly damaged nearby houses.

"We have reports of civilian casualties, there are also reports that four women and three children were among the dead but we are trying to confirm it," one official said.

The missile attack also injured 13 people including women and children, another intelligence official in Miranshah earlier told AFP.

The Monday attack was the second in three days, following a similar strike in North Waziristan on Saturday which killed four militants, the official said.

Monday's strike targeted a compound used by militants in Kutabkhel village, some three kilometres south of Miranshah.

The nationalities of the militants killed in the Monday attack were not immediately clear, but intelligence officials in the area said most of them were Afghans.

Residents in Miranshah said militants linked to the Haqqani network were using the house as a training camp.

US forces have been waging a drone war against Taliban and Al-Qaeda-linked commanders in Pakistan's northwestern tribal belt, where militants have carved out havens in mountains outside direct government control.

Washington has branded the rugged tribal area on the Afghan border -- part of which has now been hit by Pakistan's catastrophic flooding -- a global headquarters of Al-Qaeda and the most dangerous place on Earth.

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.

More than 1,000 people have been killed in 117 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.

The United States has been increasing pressure on Pakistan to crack down on Islamist havens along the border.

Pakistani commanders have not ruled out an offensive in North Waziristan, but argue that gains in South Waziristan and the northwestern district of Swat need to be consolidated to prevent their troops from becoming overstretched.

Waziristan came under renewed scrutiny when Faisal Shahzad, a Pakistani-American charged over an attempted bombing in New York on May 1, allegedly told US interrogators he went to the region for terrorist training.

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.