A videograb shows mass destruction inside a mosque.

A blast tore through a mosque in Afghanistan's northeastern Kunduz province on Friday, killing at least 50 and wounding over 90 people, Taliban officials said.

"We have received more than 90 wounded patients, but the number will change. We are still receiving more people," said the hospital worker, who did not want to be named.

The powerful blast occurred in a Shiite mosque in Kunduz province during the weekly Friday prayer service.

Videos and photos on social media and elsewhere appear to show people searching the destroyed mosque and moving a worshipper's body from the gruesome scene to an ambulance.

Taliban chief spokesman Zabihullah Mujahid said the Shiite mosque was the target and that a "large number” of worshippers were killed and wounded.

He said Taliban special forces had arrived to the scene and were investigating the incident.

Witnesses in the area said they were praying when they heard the explosion.

The cause was not immediately clear.

The Taliban leadership has been grappling with a growing threat from the local Daesh affiliate.

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

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