At least 100 have been killed and many others injured in a suicide bomb blast at a Shia mosque in Kunduz during Friday prayers.
The UN mission to Afghanistan said in a tweet that the suicide blast killed and wounded more than 100 people.
Deputy Police Chief for Kunduz province, Dost Mohammad Obaida, corroborated the UN figure.
The state-run Bakhtar News Agency said more than 140 were wounded inside the mosque in the Khan Abad area of Kunduz city.
This is the worst attack since the Taliban takeover in August, according to observers.
The Islamic State claimed responsibility for the attack on its Telegram channels on Friday.
Since the Taliban takeover of Afghanistan in mid-August, attacks by ISIL (ISIS)-affiliated fighters against them have increased.
The rise has raised the possibility of a wider conflict between the two groups.
