The attack occurred during Friday prayers at the Sayed Abad mosque in Kunduz, Rohani said.
A Taliban spokesman said security forces were on the scene and an investigation was underway.
ISIS-K claimed responsibility for the blast, according to a statement released by the group’s media wing, Amaq. It added that a suicide bomber detonated his explosive vest among Shia worshipers inside a mosque during Friday Prayers in Khan Abad district of Kunduz.
Friday’s mosque bombing “is part of a disturbing pattern of violence” and the third deadly attack this week “apparently targeting a religious institution,” the UN mission in Afghanistan (UNAMA) said on Twitter.
The Islamic State affiliate IS Khorasan (ISIS-K) claimed responsibility for Monday’s bombing, one of a series of attacks the terror group has launched since the Taliban seized control of Afghanistan more than a month ago. Others include a suicide attack at Kabul’s airport in August and a spate of bombings targeting members of the Taliban in the eastern Afghan city of Jalalabad.
The group poses a threat to the country’s stability and the Taliban’s rule. In recent days, the Taliban have conducted several operations targeting ISIS-K militants.
The Taliban claimed to have killed at least nine ISIS-K members and detained five others in two operations last week, targeting ISIS hideouts in the central Afghan province of Parwan, according to local Taliban police chief Maulvi Abdul Qadir Haqqani.