A US drone killed at least eight militants Friday when it fired two missiles on a vehicle in Pakistan's tribal badlands near the Afghan border, security officials said.

The attack took place in the Shaktoi area of South Waziristan, part of the tribal belt that Washington considers a global hub of Taliban and Al-Qaeda militants.

"A drone fired two missiles on a vehicle. At least eight militants were killed," a senior security official told AFP. "It is not immediately clear if some important target was hit in the missile strike."

Another security official based in Peshawar and an intelligence official based in South Waziristan confirmed the attack and death toll.

The area is a stronghold of militants belonging to Tehreek-e-Taliban Pakistan, an umbrella militant group led by warlord Hakimullah Mehsud.

Local tribesmen said that after the missile strike militants immediately cordoned off the area and began pulling out their colleagues from the burning wreckage.

"The bodies of militants were badly burnt in the fire and I saw some of them putting small body parts in plastic bags," a resident told AFP, asking not to be named.

"Militants cordoned off the area and fired gunshots in air to keep the locals away," he added.

US officials say Pakistan's tribal belt is a sanctuary for Taliban fighting in Afghanistan, Al-Qaeda groups plotting attacks on the West, Pakistani Taliban who routinely bomb Pakistan, and other foreign fighters.

The Obama administration is looking to withdraw all foreign combat troops from Afghanistan by the end of 2014.

But the missile attacks fuel widespread anti-American resentment in Pakistan, which has been running especially high since US air strikes inadvertently killed 24 Pakistani soldiers in November.

President Barack Obama in January confirmed for the first time that US drones target Taliban and Al-Qaeda militants on Pakistani soil, but American officials do not discuss details of the covert programme.

According to an AFP tally, 45 US missile strikes were reported in Pakistan's tribal belt in 2009, the year Obama took office, 101 in 2010 and 64 in 2011.

The New America Foundation think-tank in Washington says drone strikes have killed between 1,715 and 2,680 people in Pakistan in the past eight years.

US diplomatic cables leaked by WikiLeaks in late 2010 showed that Pakistan's civilian and military leaders privately supported US drone attacks, despite public condemnation in a country where the US alliance is hugely unpopular.

But Pakistan is now reviewing its entire alliance with the United States in the wake of the November deaths and has kept its Afghan border closed to NATO supply convoys since then.

It ordered US personnel to leave the Shamsi air base in southwestern Pakistan, widely believed to have been a hub for the CIA drone programme, and is thought likely to impose taxes on convoys if it reopens the Afghan border.