|A US drone has reportedly crashed in South Waziristan, the second such incident in a month [EPA]
Heavily armed Taliban fighters have stormed a police post in Pakistan's tribal border area, triggering clashes that left at least 15 people dead.
Sunday's violence, which lasted an hour, took place in the town of Bara, in the Khyber tribal agency close to the Afghan border, local officials said.
More than 50 Taliban fighters armed with sophisticated weapons attacked the police post, where anti-Taliban armed groups were also present to help the police, local official Sayed Ahmad Jan told the AFP news agency.
A policeman and four anti-Taliban fighters were killed in the raid, which was repulsed after an hour when troops intervened, forcing the Taliban to flee.
"Troops rushed to the spot and killed 10 Taliban militants in the retaliatory fire," Ahmad said. "The situation is now under control."
The checkpoint is on an important supply route used by NATO forces into Afghanistan.
More than 4,600 people have been killed across Pakistan in attacks blamed on Taliban and other Islamist networks based in the tribal belt since government troops stormed a radical mosque in Islamabad in 2007.
In a separate development, an unmanned US drone aircraft crashed in a northwestern tribal district on Saturday night, sparking a battle between Pakistani troops and the Taliban near where the debris fell.
The drone, the second one to crash in Pakistan within the last month, went down in South Waziristan, part of the troubled tribal belt on the Afghan border.
Local officials said the drone crashed after suffering a technical fault, but the Taliban claimed they had shot down the aircraft .
"The American drone crashed in Zangara village of South Waziristan, apparently because of some technical faults," a security official in Peshawar, the main town in Pakistan's northwest, told AFP.
Two intelligence officials in Wana, the main town of South Waziristan, confirmed the incident. It was an armed Predator drone, they said.
"A search operation is continuing to recover the debris," added a senior security official in Peshawar, saying that a group of fighters fired on troops during the search operation but fled after retaliatory fire.
"We have no reports of loss of life on both sides," he added.
Missile-armed drones have been playing a greater role than ever in US counterterrorism operations in Pakistan's northwest, which President Barack Obama has described as "the most dangerous place in the world".
Abu Hafs al Shahri, a Saudi national who had been the senior figure in al-Qaeda's central command, was recently killed by a drone strike in the area, two US officials said.
The drone strikes have been a major source of friction in ties between the US and Pakistan, which are at their worst since US special forces killed al-Qaeda leader Osama bin Laden in a secret raid in a Pakistani military town in May.
While Pakistan often publicly opposes the strikes, the government has privately allowed them and co-operated with the US in determining targets.