Gunmen intercepted two minibuses travelling through central Afghanistan and killed at least 14 passengers overnight, officials said on Friday.
Local officials in the remote, mountainous province of Ghor said most of the passengers were from the ethnic Hazara Shi'ite minority, but that could not be independently verified.
"The insurgents stopped two vans and after checking peoples' identifications cards, they separated 14 passengers from 32 others and shot them dead," said provincial governor Sayed Anwar Rahmati.
At least three women and a three-year-old child were among those killed.
Sediq Sediqqi, an interior ministry spokesman, accused Taliban insurgents of carrying out the attack, saying it was "aimed at instilling fear in the people".
The Taliban denied involvement.
"The Islamic Emirate strongly condemns the killings and will try to find and punish the perpetrators," Taliban spokesman Zabihullah Mujahid said in a text message to Reuters, referring to the government toppled by U.S.-led forces over 12 years ago.
The Taliban, an austere Sunni militant group that ruled Afghanistan from 1996 to 2001, has been fighting U.S.-led and Afghan forces since they were removed after the Sept 11, 2001 attacks on U.S. targets.
Many of the Hazaras - believed to be descended from Mongol invaders - suffered enormously under Taliban rule and the Shi'ite minority saw many of its communities levelled.
Many were killed and buried in mass graves or thrown into wells. They still believe they are treated as second-class citizens and that President Hamid Karzai has done little to improve their lot.