The attack took place during Friday prayers at the Syed Abad Mosque in Kunduz, Rohani said.
A Taliban spokesman said security forces were at the scene and an investigation was underway.
ISIS-K claimed responsibility for the blast, according to a statement from the group’s media unit. A suicide bomber detonated his explosives among Shia worshipers inside a mosque during Friday prayers in Khan Abad district of Kunduz.
The UN mission in Afghanistan (UNAMA) said on Twitter that Friday’s mosque bombing was “part of a chaotic form of violence” and that this week’s third deadly attack “apparently targets a religious organization”.
ISIS-K (ISIS-K) has claimed responsibility for Monday’s bombings, one of a series of terrorist attacks since the Taliban seized control of Afghanistan a month ago. Others include a suicide bombing at Kabul airport in August and a bomb blast targeting Taliban members in the eastern Afghan city of Jalalabad.
This group is a threat to the stability of the country and the rule of the Taliban. In recent days, the Taliban have carried out a number of operations targeting ISIS-K militants.
Local Taliban police chief Malvi Abdul Qadir Haqqani said at least nine ISIS-Q members had been killed and five others arrested by the Taliban in two operations last week targeting ISIS hideouts in central Afghanistan.