An explosion ripped through a mosque in Kunduz province on Friday afternoon, killing at least 50 people and wounding 90 others, local officials said. 

The blast took place inside the Sayyidabad mosque in the Khanabad Dandar area Kunduz’s Khanabad district while dozens of people were attending Friday prayer.

Zabihullah Mujahid, a spokesman of the Islamic Emirate of Afghanistan (IEA), said that the explosion targeted a mosque where the Shiite religious minority worship.

“This afternoon, an explosion took place in a mosque of our Shiite compatriots in the Khanabad Dandar area in the center of Kunduz province, as a result, a number of our compatriots were martyred and wounded,” Mujahid said. 

He added that a special unit of the IEA have been deployed to the attack site.

Mujahid noted that the incident is being investigated.

The United Nations Assistance Mission in Afghanistan (UNAMA), meanwhile, said that it was deeply concerned by reports of very high casualties in the attack.

“Today’s incident is part of a disturbing pattern of violence: 3rd deadly attack this week apparently targeting a religious institution. Islamic State (KP) claimed responsibility for Sunday’s incident next to a Kabul mosque. Wednesday’s attack on a madrassa in Khost unclaimed,” UNAMA tweeted.

ISKP, locally known as Daesh, has claimed responsibility for the attack.