Dawlat Waziri, a spokesman for Afghanistan's defence ministry, said the strike was carried out by foreign forces in coordination with Afghan officials.
The incident took place Thursday evening in the Haska Mina district of Nangarhar province.
On July 24, Afghan officials said, nine civilians were killed in a US airstrike on a prayer ceremony held in Haska Meena district by relatives of Islamic State members who had previously been killed.
But Bob Purtiman, a spokesman for the American military in Afghanistan, dismissed the official assertions.
He said "The strike was conducted in the middle of open terrain".
This is the second strike in the last few weeks in the district which killed civilians.
Civilian casualties caused by North Atlantic Treaty Organisation forces have been one of the most contentious issues in the close to 16-year campaign against insurgents, prompting strong public and government criticism.
Afghan officials today confirmed that United States airstrikes targeted and killed at least 16 civilians, mostly women and children, in the eastern Nangarhar Province, targeting the civilians as they tried to flee out of an ISIS-held district where heavy fighting has been ongoing.
Several districts of Nangarhar are infested with IS militants, USA and Afghan officials said.
Faryab province, with Maimana as its capital, has been the scene of Taliban-led insurgency over the past decade.
Civilian deaths are at an all-time high in Afghanistan.
Meanwhile, the U.N Assistance Mission in Afghanistan (UNAMA) said it had completed its probe into the killings of dozens of civilians in the northern province of Sar-e-Pul and promised to issue its findings soon. Women and children were among the victims.