A US drone crashed in northwest Pakistan's tribal district near the Afghan border late Saturday, officials said.

The unmanned aircraft came down in the mountainous Machikhel area about 30 kilometres (20 miles) east of Miranshah, the main town in North Waziristan region, which is frequently targeted by drone strikes against Taliban and Al-Qaeda militants, military and security officials said.

"A US drone crashed, apparently due to some technical fault," a military official in the northwestern city of Peshawar told AFP.

Security officials in the region confirmed the crash saying it fell in the mountains.

The crash site has been surrounded by militants, one security official said, refusing to confirm claims by some Taliban that the drone was shot down by insurgents.

President Barack Obama last month 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.

The US strikes are deeply unpopular among the Pakistani public, who see the attacks as a violation of sovereignty and who blame the government's US alliance for much of the violence plaguing the country.

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 programme has dramatically increased as the Obama administration looks to withdraw all foreign combat troops from Afghanistan by the end of 2014.