March 6 (UPI) -- More than two dozen people were killed Friday at a ceremony in Kabul, Afghanistan, that included some of the nation's political elite, authorities said.
Afghan Interior Ministry spokesman Nasrat Rahimi said at least 27 people were killed in the shooting attack at the gathering, which was attended by Afghanistan Chief Executive Abdullah Abdullah, former President Hamid Karzai and other high-ranking figures.
Abdullah's deputy, Mohammad Mohaqiq, said the officials were all unharmed.
The Taliban denied responsibility for the attack, which was the first violent incident in Kabul since the the signing of a peace deal a week ago between U.S. officials and the militant group that was intended to set a path to further negotiations involving the Afghan government and lead to a complete withdrawal of U.S. forces.
Afghan President Ashraf Ghani called the assault "barbaric" and "a crime against humanity."
"The Afghan government condemns the attack in the strongest terms," he said. "The brave security forces will take any possible action to repel the attack and protect the people."
Rahimi said the gunfire appeared to come from a construction site across the street.
The dignitaries gathered in the capital Friday to mark the 25th anniversary of the death of revered Shiite political leader Abdul Ali Mazari. The same event was also attacked last year and nearly a dozen people died. An affiliate of the Islamic State claimed responsibility.
The Islamic State has been behind a series of bombings in Kabul in recent years that targeted the city's Shiite population. The U.S. military, Afghan government and the Taliban have all carried out offensives targeting Islamic State fighters.
U.S. Secretary of State Mike Pompeo called the attack a "sign of weakness, not a show of strength."
"The Afghan people deserve a future free from terror. The ongoing Afghan peace process presents a critical opportunity for Afghans to come together to build a united front against the menace of ISIS," he added, using an acronym for the Islamic State.