Rohullah Azizi, the brother of former Afghan Vice President Amrullah Saleh, was slain by the Taliban on Friday, according to Aamaj News.
According to Aamaj, Azizi was apprehended and shot on Thursday in Panjshir's Rokha district.
His brother Saleh, unlike former President Ashraf Ghani, did not depart the country. He rose to become one of the Taliban's most powerful opponents. His precise location is unclear.
Panjshir, the final stronghold of the anti-Taliban resistance organization National Resistance Front of Afghanistan (NRF), was taken over by the Taliban this week.
Resistance commander Ahmad Massoud, on the other hand, insisted on continuing the war and called for a nationwide revolt.
Protests in support of Massoud's movement erupted around the country in response to his requests.
On the other hand, the Taliban declared the protests illegal, and the UN accused the Taliban of using violence to disperse them.
The Taliban retaliated with live bullets, batons, and whips, according to UN rights spokesman Ravina Shamdasani, killing at least four protestors.