A major salvo of U.S. missiles on Wednesday destroyed a Pakistani Taliban base on the Afghan border, killing up to 18 militants including possible Al-Qaeda fighters, local officials said.

Five U.S. drones fired up to 10 missiles into a sprawling compound in the Baber Ghar area of South Waziristan, killing 15 to 18 fighters in the deadliest such American strike in three months, the Pakistani officials said.

U.S. officials say Pakistan's tribal belt provides sanctuary to Taliban fighting for 10 years against American troops in Afghanistan, Al-Qaeda groups plotting attacks on the West and Pakistani Taliban who routinely bomb Pakistan.

Five U.S. drones carried out Wednesday's attack, one of the officials told AFP in the deadliest such coordinated strike in northwest Pakistan since a similar strike killed 21 fighters in the Afghan Taliban Haqqani faction on August 10.

"The target was a base of Pakistan Taliban. We have reports that 16 to 18 militants were killed," the official told AFP in the northwestern city of Peshawar. Another official in Peshawar put the death toll at 15.

An official in Wana, the main town of South Waziristan, confirmed that a base of Pakistan's umbrella Taliban faction, Tehreek-e-Taliban, was destroyed and said there were reports that "some foreigners" were also killed.

Pakistani officials typically use the word "foreigner" to denote Al-Qaeda and Uzbek Islamist militants.

"It was Taliban base. They were using this place as a training camp, to keep weapons and to take shelter," the Wana official said. "The drones came almost at the same time," he added.

Officials said the attacks came minutes apart at around 2:30 am (2130 GMT Tuesday) about three kilometres (two miles) from the border of Afghanistan's Paktia province, one of the flashpoints in the 10-year Taliban insurgency.

Wednesday's strike was the 63rd so far this year, according to an AFP tally.

Elsewhere in the tribal belt on Wednesday, an army officer and a soldier were killed in separate Taliban attacks on convoys in the troubled district of Kurram and in Ladha town in South Waziristan, security officials told AFP.

Both officials requested anonymity as they were not authorised to talk to the media.

"Several militants were also killed in retaliatory fire," one official said of the Kurram attack.

The United States refuses to discuss publicly drone strikes in Pakistan, but the programme has dramatically increased as the Obama administration searches for an end to a decade of fighting in Afghanistan.

The Pakistani government has quietly assented to the programme despite popular opposition at home, where anti-Americanism is frequently exploited by nationalist politicians and the conservative religious right.

The drone strikes have also been credited with killing some of Islamabad's biggest enemies -- such as Baitullah Mehsud, the founder of Pakistan's Taliban movement blamed for the majority of bomb attacks that have killed thousands.

Pakistan-US ties deteriorated sharply this year over a unilateral American raid that killed Osama bin Laden in May and over accusations that Pakistani intelligence was involved in a September siege of the US embassy in Kabul.

At talks in Islamabad last month, US Secretary of State Hillary Clinton called on Pakistan to take action within "days and weeks" on dismantling Afghan militant havens and encouraging the Taliban into peace talks.

But with Islamabad a key ally in the war in Afghanistan -- the bulk of NATO supplies still route through Pakistan to landlocked Afghanistan -- US action against militants on Pakistani soil is limited to the covert drone strikes.

There is also a growing debate in Washington about further limiting aid to Pakistan, perceived to play a double game with the Taliban, unless the government does more itself to neutralise the threat.