At least 100 people have been killed or wounded in an explosion targeting Shiite Muslims at a mosque in northern Afghanistan, according to a Taliban police official.

Dost Mohammad Obaida said the “majority of them have been killed”.

The blast occurred during the Friday prayer service at the Gozar-e-Sayed Abad Mosque in Kunduz province, when members of the Shiite minority typically go in large numbers for worship.

If confirmed, the death toll would be the highest in an attack by militants since US and Nato troops left Afghanistan at the end of August and the Taliban took control.

Witness Ali Reza said he was praying at the time of the explosion and reported seeing many casualties.

Taliban chief spokesman Zabihullah Mujahid said Taliban special forces had arrived at the scene and were investigating the incident.

The cause of the blast was not immediately clear. No group has claimed responsibility.

The Taliban leadership has been grappling with a growing threat from the local affiliate of the so-called Islamic State group, known as the Islamic State in Khorasan.

IS militants have ramped up attacks to target their rivals, including two deadly bombings in Kabul.

IS has also targeted Afghanistan’s religious minorities in attacks.