Witnesses and the Taliban's spokesman said numerous people were killed in a massive explosion in a mosque frequented by a religious minority group in northern Afghanistan on Friday.

The incident occurred during a weekly Friday prayer service at the Gozar-e-Sayed Abad Mosque in Kunduz province. Members of the Shiite religious minority regularly gather in large numbers for worship. Ali Reza, a witness, said he was praying at the explosion and saw numerous casualties.

According to Taliban spokesman Zabihullah Mujahid, the Shiite mosque was targeted, and a "large number" of people were killed or injured. Taliban special troops had arrived on the location, he claimed and were looking into the event.

The cause of the explosion remained unknown at the time. Any group has not yet claimed it.

The local Islamic State affiliate, known as the Islamic State in Khorasan, poses a rising danger to the Taliban leadership. IS terrorists have up their attacks on their opponents, including two deadly bombings in Kabul.

IS has also launched attacks against Afghanistan's religious minorities.