Zabihullah Mujahid, a Taliban spokesperson, said Pakistani aircraft struck civilian homes in Khost and Paktika provinces near the border with Pakistan at around 3:00 a.m. local time (2230 GMT).
According to Mujahid, all eight people killed were women and children.
Mujahid condemned the airstrikes and warned that such "violation of Afghanistan's sovereignty" will bring "bad consequences" beyond its neighbor's control.
This is the latest escalation as tensions between Islamabad and Kabul simmer.
The airstrikes targeted multiple suspected hideouts of Pakistani Taliban inside Afghanistan, two Pakistan security officials told AP news agency. The Pakistani Taliban is a separate militant group but allied with the Afghan Taliban.
The early morning strikes came two days after a suicide bombing targeted a Pakistan army post near the Afghan border.
On Satrday, a suicide bomber had rammed a truck filled with explosives into a military checkpoint in northwest Pakistan, killing seven soldiers.
During the funeral of the soldiers, Pakistani President Asif Ali Zardari promised a strong response.
"The blood of our martyred soldiers will not go in vain," Zardari said.
Saturday's suicide attack was claimed by the Jaish-e-Fursan-e-Muhammad group, though security officials in Pakistan believe that the organization largely consists of members from the banned Tehrik-e-Taliban Pakistan, or TTP.
MNA/PR