The New York Times reported earlier Friday that Afghan officials said US aircraft killed 16 civilians as they tried to flee the area. Saaz Wali Shinwari, the district governor of Haska Mina in Nangarhar province, said the raid was carried out by U.S. troops although there was no official confirmation from North Atlantic Treaty Organisation.
USA forces in Afghanistan on Friday denied allegations by Afghan officials that a US airstrike killed 16 civilians in eastern Afghanistan.
"The militants were observed loading weapons into a vehicle and were under surveillance until the vehicle was destroyed by an airstrike", said Bob Purtiman, a spokesman.
"On Thursday afternoon, the USA forces bombarded a civilian private vehicle. when they were travelling inside the district", Saaz Wali Shinwari, the district governor of Haska Mina in Nangarhar province, told AFP.
He said "The strike was conducted in the middle of open terrain".
Several districts of Nangarhar are infested with IS militants, USA and Afghan officials said.
Civilian casualties caused by North Atlantic Treaty Organisation forces have been one of the most contentious issues in the close to 16-year military campaign in Afghanistan, prompting strong government and public criticism.
Faryab province, with Maimana as its capital, has been the scene of Taliban-led insurgency over the past decade.
But US Forces-Afghanistan said in a statement on Saturday that the airstrike "killed a number of militants", not civilians. Civilian deaths are at an all-time high in Afghanistan.
The United States military has deployed Special Forces and airstrikes against Islamic State group militants in Afghanistan and said it has killed dozens of the group's leaders and hundreds of fighters this year.
UNAMA, however, urged all parties to refrain from exploiting harrowing events for political purposes and before basic facts were established.