The UN office in Kabul revealed the figure of casualties following an explosion at a mosque in district 11 of Kabul on August 17.
According to the Taliban, 21 people had been killed and 23 others had been injured because of the Wednesday evening explosion at the mosque in Kabul. Some sources reported an even higher number of casualties.
UNAMA has also expressed its sympathy to the families of the victims and stressed that many civilians were killed and injured in the attack.
The UN agency did not provide further details about the exact number of casualties in Wednesday's attack.
With the security situation deteriorating in Afghanistan, UNAMA urged the Taliban authorities to take concrete steps to prevent all forms of terrorism in Afghanistan.
UNAMA has said that the Taliban should provide additional support to vulnerable communities in Afghanistan.
Despite the large-scale attacks and the increase in the number of civilian casualties, Taliban officials claim that Afghanistan is safe and the group is in control of the security situation of the country.