At least 80 people were killed and 231 wounded in twin explosions that ripped through crowds of Shiite Hazaras in Kabul, an attack claimed by the Islamic State terror group. Members of Afghanistan's Hazara minority were demonstrating over the route of a planned multimillion dollar power line at Dehmazang square in Kabul when explosions struck the peaceful protest.
Afghanistan's President Ashraf Ghani said he was "deeply saddened" by the carnage, adding that "peaceful protest is the right of every citizen".
Condolences continued to pour in from across the world on the attack on the Persian-speaking Shia community that has threatened to exacerbate ethnic tensions among other groups.
'A despicable crime'
United Nations Secretary-General Ban Ki-moon led the world body's strong condemnation of the terror attack in Afghanistan, describing it as a "despicable crime" while calling for bringing to justice the perpetrators of the assault.
According to a statement issued by his office, Ban called for those responsible for the attack to be brought to justice.
"The Secretary-General condemns the terrorist attack in Kabul. This despicable crime targeted citizens peacefully exercising their fundamental human rights," the statement said.
The powerful UN Security Council also issued a statement, condemning "in the strongest terms" the "heinous and cowardly" terror attack yesterday.
"The members of the Security Council reiterated their serious concern at the threats posed by the Taliban, al-Qaeda, Islamic State in Iraq and the Levant (ISIL), illegal and armed groups to the local population, National Defense and Security Forces and international presence in Afghanistan," the statement said.
The 15-nation Council underlined the need to bring perpetrators, organisers, financiers and sponsors of these "reprehensible" acts of terrorism to justice and urged all UN member nations to cooperate actively with the Afghan authorities in this regard.
"The members of the Security Council stressed the need to take measures to prevent and suppress the financing of terrorism, terrorist organisations and individual terrorists," in accordance with UN resolutions.
Asserting that terrorism in all its forms and manifestations is criminal, the Council said terrorism should not be associated with any religion, nationality, civilisation or ethnic group.
The Council reiterated that "no violent or terrorist acts" can reverse the Afghan-led process along the path towards peace, democracy and stability in Afghanistan, which is supported by the people and the Afghan government and by the international community.
Head of the UN Assistance Mission for Afghanistan Tadamichi Yamamoto called the attack "an outrage that cannot be justified and stressed that the perpetrators of the attack must be held accountable."
"An attack deliberately targeting a large, concentrated group of civilians amounts to a war crime," he said in the statement, which was issued by UNAMA.
"This attack is particularly heinous because it targeted civilians as they exercised their rights to freedom of assembly and freedom of expression," Yamamoto said.
UN General Assembly President Mogens Lykketoft expressed his deepest sorrow and anger over the terrible terror attacks and "mass murders" taking place around the world.
'Inhumane and un-Islamic', says Iran
Iranian foreign minister Mohammad Javad Zarif condemned the attack and expressed grief.
"Afghanistan terror bombings another instance of depth of Daesh depravity: Shia and Sunni are both victims & must unite to defeat extremists," Zarif tweeted on Saturday, using another name for the Islamic State.
Foreign ministry spokesman Bahram Ghasemi added that "eradicating this unfortunate phenomenon wouldn't be possible without a joint cooperation and understanding among all countries".
The "inhumane and un-Islamic" attacks were "unjustifiable anywhere," he added.
The first major IS assault on Kabul was apparently aimed at sowing sectarian discord in a country known for relative Shia-Sunni harmony.
Iran, a country with a large Shiite majority, has a long border with Afghanistan.
Pakistan expresses grief
Pakistan's Foreign Office (FO) on Sunday said in a statement, "The government and the people of Pakistan extend their sincere condolences and profound sympathies to the families of the bereaved people and convey their earnest prayers and wishes for early recovery of those injured in this heinous act of terrorism."