Afghan Special Forces, backed by U.S. partners, are being accused of killing nine civilians and injuring eight others in eastern Nagarhar province, apparently mistaking them for Islamic State militants.
A provincial government spokesman told VOA Tuesday a majority of the victims from the overnight incident in the volatile Chaprahar district were family members of the chairman of Afghanistan's Senate, the upper house of parliament.
Attaullah Khogyani said a local police commander and his two armed guards were also among those killed. He added that an investigation was launched to determine what prompted Afghan Special forces to undertake the Monday night operation in the area without coordinating it with provincial security institutions.
The central Afghan government has only said it has sent a high-level delegation to investigate the deadly incident, added Khogyani.
"This was an Afghan-led operation. No U.S. Forces-Afghanistan personnel were involved in this operation," the U.S. military said.
Ghulam Haidar Faqirzai, head of the provincial department for refugees and returnees, told VOA the unexpected arrival of security forces in the area in the middle of the night provoked locals to take up arms in self defense believing IS terrorists had attacked them.
That was when Afghan special forces reacted and opened fire on them, said Faqirzai, who also hails from the village where the deadly clash occurred.
A large number of the victims were related to Senate Chairman Fazil Hadi Muslimyar, the official added.
IS runs bases in several southern districts of Nangarhar, including Chaprahar.Afghan Special Forces, with the support of U.S. airstrikes and military advisers, routinely conduct counterterrorism operations in these areas and have killed hundreds of IS fighters.
Civilians continue to bear the brunt of intensified hostilities in Afghanistan.
The United Nations says more than 10,000 civilians were killed or wounded in 2017 and the number of casualties remain high in the current year.
An Afghan Air Force airstrike in April killed 36 civilians, including 30 children in the northern Kunduz province where Taliban insurgents control or strongly contest several districts.
Afghan authorities from the outset had insisted the strike targeted insurgents until a U.N. probe proved them wrong, prompting President Ashraf Ghani earlier this montht o offer a public apology for the deadly incident.