"Two missiles were fired at the house of a tribal elder where local militants were present," one security official said on the condition of anonymity as he is not authorised to speak to media.
"Four dead bodies have been recovered and two are injured," the official added.
Shin Warsak is 15 kilometres (nine miles) west of Wana, the main town of the district of South Waziristan, considered a militant stronghold.
The security official said initial reports suggested that a group of local militants were present in the house at the time of the attack.
Two other Pakistani intelligence officials confirmed the drone strike and death toll.