"The United Nations condemns the attack today on religious scholars gathered in Kabul to promote peace in Afghanistan. Attacks on civilians are war crimes. Such attacks must not deter our collective resolve for a peaceful future for all Afghans," UNAMA said in a Twitter message.
Earlier in the day, at least 14 civilians were killed and 17 more were injured in an explosion targeting a gathering of top Afghan clerics in Kabul, according to TOLOnews.
The religious scholars had just left a meeting in which they issued a joint fatwa, an Islamic ruling, condemning the ongoing conflict and suicide bombings in Afghanistan, media reports added.
No terrorist organization has immediately claimed responsibility for the attack.