Dozens of civilians, including children, have been killed in an Afghan air attack on a gathering at a religious school in the northern province of Kunduz, eyewitnesses and an official said.

A religious school in the Dasht-e-Archi district of the Kunduz province was targeted by air raids late on Monday, resulting in the death of at least 70 people, including top Taliban commanders, a district official told Al Jazeera on the condition of anonymity.

Ministry of Defense spokesman, Mohammad Radmanish, told Al Jazeera that the air raid was aimed at "top Taliban commanders".

The Taliban denied its fighters were present at the school during the time of the attack.

Witnesses told Al Jazeera that the gathering included "a lot of civilians" and the families of those killed in the attack' were devastated".

"There were children as young as 11 or 12 years old in the ceremony who were to be presented with awards and gifts for the completion of their religious courses," Mohammed Abdul Haq, who witnessed the attack, told Al Jazeera.

Other witnesses told Al Jazeera that more than 100 people were killed in the attack.

United Nations Assistance Mission in Afghanistan said on Twitter that a human rights team on the ground will investigate the incident.

"UNAMA actively looking in to disturbing reports of serious harm to civilians yesterday from air strike at #DashtiArchi, #Kunduz. Human Rights team on ground establishing facts. All parties reminded of obligations to protect civilians from impact