The attack happened in Shakai, a town in the South Waziristan tribal region, near the Afghan border.
Malik Khajan, the tribal elder, was among the dead, intelligence officials said on the condition of anonymity because they were not authorised to speak to the media.
Pakistan's military could not immediately confirm the incident.
One of the officials said Khajan had lead a campaign in recent months to evict foreign fighters from Shakai, and that authorities suspected that the attack was launched by al-Qaeda-linked Uzbek fighters or their supporters.
The attack in Shakai comes amid escalating tensions in Pakistan's lawless tribal region.
On Wednesday, 42 Pakistani soldiers were killed and scores wounded when a man blew himself up at a military base in the Bajur region.
A previously unknown pro-Taliban group claimed it carried out the attack to avenge an army airstrike on an Islamic boarding school last week that killed 80 people.