Mohammad Mohaqiq said two former Taliban leaders, who switched allegiance to the rival Islamic State group, were responsible for the abduction of 31 members of the minority Shiite Hazara community on February 24 in southern Zabul province.
He spoke with The Associated Press today. It is the first time an Afghan leader has confirmed Islamic State group involvement in the kidnappings.
Mohaqiq, who is a deputy to Afghanistan's Chief Executive Abdullah Abdullah, named Mullah Abdullah Kaka and his deputy Mullah Mansur Dadullah as behind the abductions.
Muhaqiq says the two prominent Islamic militants have simply "changed their white flag" of the Taliban for the black IS flag. Afghan security forces had launched an operation to find the Hazaras in the week after the kidnappings, Mohaqiq said, but the effort failed.
The men have now been split up into three or four groups and were being held in different areas of the mountainous province, Mohaqiq said. As far as he knew, they were still alive.
The Hazaras were abducted from two vehicles on a major road in Zabul province by men said by officials at the time to be wearing black clothing and black masks. The armed kidnappers separated the men and boys from women, children and non-Hazaras in the vehicles.
Hazara people, who account for as much as 25 per cent of Afghanistan's population, are mainly Shiite. The group has been targeted by the Taliban and other Sunni extremists, who view Shiites as apostates.
The predominantly ethnic Pashtun and Sunni Taliban persecuted the Hazara minority during their 1996-2001 rule, when they imposed a harsh version of Islamic law on the country.
The presence in Afghanistan of the Islamic State group, which controls about a third of Iraq and Syria and is known for its extreme violence, is widely acknowledged but officials have been reluctant to confirm the involvement of the group in the Hazara kidnappings.