The Taliban government's regional official said the attack was committed by a suicide bomber during Friday prayers.
Dozens of people have been killed after an explosion at a Shiite Muslim mosque in northern Afghanistan.
A local Taliban police official has said that at least 46 worshippers have been killed in the blast, which occurred during weekly Friday prayers.
Photos and video from the scene showed rescuers carrying a body wrapped in a blanket from the mosque to an ambulance.
A regional Taliban government spokesperson told AFP that the blast at the Gozar-e-Sayed Abad Mosque was caused by a suicide bomber.
The militant so-called Islamic State group has claimed responsibility for the blast, which took place in Kunduz province and injured an estimated 143 others.
The death toll in the attack is the highest since US and NATO forces left Afghanistan at the end of August.
Militants have a long history of attacking Afghanistan's Shiite Muslim minority and the bombing comes just five days after a deadly attack in Kabul that was also claimed by the so-called Islamic State.
An investigation has been launched into the explosion, as emergency services remain at the scene.
"This afternoon, an explosion took place in a mosque of our Shiite compatriots in the Khan Abad district of Bandar, the capital of Kunduz province," the chief Taliban spokesman Zabihullah Mujahid said on Twitter.
"A number of our compatriots were martyred and wounded," he said, adding that Taliban special forces had arrived at the scene.
The Taliban government have since been targeted in a series of deadly attacks, including shooting ambushes and an explosion at a mosque in the capital of Kabul.
The so-called Islamic State has also targeted Afghanistan's religious minorities in attacks.
The United Nations mission in Afghanistan condemned Friday's attack, saying it was "part of a disturbing pattern of violence" targeting religious institutions.
A local militant affiliate also claimed responsibility for a bombing that killed at least 169 Afghans and 13 US military personnel outside the Kabul airport on August 26.