Six suspected militants were killed Thursday when a missile apparently fired by a US drone struck a house in a Pakistani tribal district known to be a Taliban stronghold, an official said.

The missile hit a house next to a seminary in South Waziristan district in the country's north west, the senior Pakistani security official told AFP.

Local intelligence officials confirmed the strike, saying the missile destroyed the house and damaged the seminary.

There were no immediate indications that any high-ranking Taliban militants were killed in the attack, which appeared to be the latest in a series of strikes from unmanned drones against suspected militant hideouts in tribal areas of Pakistan.

Washington has stepped up its missile strikes against suspected Al-Qaeda and Taliban hideouts in tribal areas bordering Afghanistan in recent months, despite protests by Islamabad.

A missile attack late last month by a US jet killed Rashid Rauf, the alleged Al-Qaeda mastermind of a 2006 transatlantic airplane bombing plot, as well as an Egyptian Al-Qaeda operative, security officials have said.

The strikes have continued despite a warning by Taliban militants based in tribal territory last month that any more would lead to reprisal attacks across Pakistan.

Al Qaeda network chief Osama bin Laden is widely believed to be hiding in the border territory, although there is no clear information about his whereabouts.