A drone strike killed four people in Pakistan's lawless North Waziristan region on Friday, possibly including a senior Pakistani Taliban commander, intelligence sources said.
Four missiles were fired at a compound in Danda Darpa Khel, a village about 5 km (3 miles) from the regional capital of Miran Shah.
North Waziristan is the stronghold of the Taliban insurgency and shares a border with Afghanistan.
Two intelligence officials said the dead were militants. Another regional security source said militants had blocked all access points to the area, making it difficult to verify information on the ground.
One Pakistan army source told Reuters separately the military were checking reports that a top Taliban commander might have been killed in the attack.
"If these reports are true, it's obviously a victory for counter-terrorism," the source said.
There was no official comment from neither the government nor the Taliban.
Pakistan publicly opposes drone strikes although some government officials have admitted the strikes had limited support among Pakistani officials.
The United States has carried out 377 drone strikes in Pakistan since 2004, the Bureau of Investigative Journalism says, with the death toll put at between 2,525 and 3,613. Based on local media reports, the Bureau estimates that between 416 and 948 of the dead were civilians.
Most of the dead are militants although their rank is often unclear, residents, militants and Pakistani security sources have told Reuters.
The government forbid most journalists from travelling to the areas where the strikes take place and the Taliban frequently seal off the sites of strikes.
Government officials frequently say militant groups have killed 40,000 Pakistanis since 2001.