At least 23 civilians, including women and children, were killed by a U.S. airstrike in southern Afghanistan earlier this week, according to a U.N. investigation, as ordinary Afghans continue to bear the brunt of the 17-year conflict.

“Initial findings indicate that the vast majority of the victims were women and children,” the United Nations Assistance Mission in Afghanistan said in a report received by AFP late Thursday, November 29 adding that at least three people were also injured in the attack.

The strike occurred during a firefight between Afghan special forces working with U.S. advisors and Taliban insurgents late Tuesday in restive Helmand province.

NATO’s Resolute Support mission said air support was requested by security forces on the ground as the militants deployed heavy weapons and retreated into a nearby compound.

Provincial authorities had earlier said several members of a single family appeared to be killed in the strike, with one official saying “at least 18 civilians were killed,” which could not be confirmed.

The Resolute Support mission said the incident was under investigation.

“We are still looking into the situation in Garm Sir, Helmand. Initial reports show that Afghan Special Security Forces were conducting an operation last night with American advisors when the Taliban fired at them,” a Resolute Support spokesperson told The Defense Post earlier this week.

“The shooters were armed with RPG’s and heavy machine guns when they retreated into a compound and continued firing at the partnered force. In self-defense, the ground force called an airstrike. After the strike, there were secondary explosions, we assess from explosives inside the compound.”

“At the time of the strike, the ground force was unaware of any civilians in or around the compound; they only knew that the Taliban was using the building as a fighting position. The Taliban continue to use civilians, especially children, as a protective measure,” the spokesperson added.

Haji Mohammad, who lived near where the incident occurred, said the strike came after the Taliban entered a home during a battle with security forces, saying it killed several civilians inside along with nine insurgents.

Afghan civilians continue to face “extreme levels of harm,” a recent United Nations report said, with 8,050 people killed or wounded in the January to September period this year.

Violence has escalated in the past year as U.S. and Afghan forces press ground and air offensives against Taliban and Islamic State Khorasan Province insurgents.

The Taliban has also upped assaults on Afghan forces even as the United States increased efforts to engage the militants in peace talks.

Washington is trying to find a way out of the conflict more than 17 years since it began.

U.S. envoy Zalmay Khalilzad is spearheading efforts to strike a peace deal with the Taliban before Afghanistan’s presidential election, scheduled for April next year though officials have said it could be postponed until July.

A Taliban delegation met with Khalilzad in Doha in October and November to discuss ending the Afghan conflict. Khalilzad has said he is “cautiously optimistic” for an end to the conflict.

With reporting from AFP