According to a leading rights group, Taliban militants massacred 13 ethnic Hazaras, most of whom were Afghan soldiers who had surrendered to the insurgency.
According to an investigation by Amnesty International, the executions took place on August 30 in the village of Kahor in Daykundi province in central Afghanistan.
Eleven of the dead were Afghan national security forces soldiers, while the other two were civilians, one of which was a 17-year-old female.
The claimed executions occurred around two weeks after the Taliban launched a blitz attack across Afghanistan, ending in their seizure of Kabul. Taliban commanders tried to reassure Afghans at the time that they had changed from their former brutal reign in the late 1990s.
The world has been watching to see if the Taliban will follow through on their promises of tolerance and inclusion for women and ethnic minorities, including Shiite Hazaras. However, the international world has expressed its displeasure with Taliban activities thus far, such as increasing restrictions on women and the appointment of an all-male cabinet.
Around 9 percent of Afghanistan's 36 million people are Hazaras. Because they are Shiite Muslims in a Sunni-majority country, they are frequently targeted.
"These cold-blooded executions (of the Hazaras) are further proof that the Taliban are committing the same horrific abuses they were notorious for during their previous rule of Afghanistan," said Amnesty International's secretary-general, Agnes Callamard.
The Taliban's Zabihullah Mujahid and Bilal Karimi did not respond to requests for comment from The Associated Press.
According to the rights group, Sadiqullah Abed, the Taliban-appointed chief of police for Daykundi, denied any killings and only stated that a Taliban member was wounded in an attack in the province.
According to the Amnesty International study, the Taliban took control of Daykundi province on August 14, and an estimated 34 former soldiers sought refuge in the Khidir district. The soldiers opted to surrender to the Taliban despite having government military equipment and firearms with them.
Mohammad Azim Sedaqat, the group's leader, arranged for the weapons to be decommissioned in the presence of Taliban militants.
According to Amnesty International's report, on August 30, an estimated 300 Taliban gunmen arrived in a vehicle near Dahani Qul hamlet, where security forces members were staying, some with family members. Taliban gunmen apprehended the security forces as they sought to leave the area with their families and opened fire on the crowd, killing a 17-year-old girl called Masuma. A soldier retaliated, killing one Taliban fighter and injuring another.
According to the story, the Taliban continued to shoot as the family retreated, killing two soldiers. According to the rights group, the Taliban brought nine security forces to a nearby river basin and executed them after they surrendered.
Amnesty International said it had verified photographs and video evidence taken after the killings.