The bullet-ridden bodies of five men were found on Sunday dumped by the side of a road in Kamsarobi village, 30 kilometres south of Miranshah, the main town in the semi-autonomous North Waziristan tribal region.
"Taliban killed five men overnight, accusing them of spying for Americans to help them launch drone attacks," local police official Mehboob Shah said.
"A note found on the body said that the victims were spying on Taliban and anyone doing the same would be killed in this manner," he added.
The body of the sixth man was found in Qutabkhel village, five kilometres (three miles) south of Miranshah, with a similar note from the Taliban, Shah said, adding that he too appeared to have been shot dead overnight.
An intelligence official and local tribesmen confirmed the incidents.
Militants frequently kidnap and kill tribesmen, accusing them of spying for the Pakistani government or US forces operating across the border in Afghanistan, where Taliban fighters are leading an insurgency.
A volley of drone strikes has hit the northwest this month, all in North Waziristan, a bastion of Al-Qaeda fighters, the Taliban and the Haqqani network, known for staging attacks on US and NATO troops in Afghanistan.
More than 740 people have been killed in about 80 US drone strikes in Pakistan since August 2008.
Separately, a paramilitary soldier was killed Sunday when Taliban fired a rocket at a convoy near Malik Deenkhel village in Khyber, another tribal district bordering Afghanistan.
"One security forces member was martyred and four others were injured after a rocket fired by militants struck their convoy," chief of Khyber administration Shafirullah Khan told AFP.
Pakistan's rugged tribal regions have been beset by violence since hundreds of Taliban and Al-Qaeda rebels fled across the border to escape the US-led invasion of Afghanistan in late 2001.
Washington says the tribal regions, where security forces are battling Islamist militants, have become a safe haven for extremists.
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