KABUL, Oct. 9 (Xinhua) -- At least 39 civilians, including 14 children and a woman, were killed in U.S.-led airstrikes on alleged narcotic-drug facilities in western Afghanistan on May 5 this year, UN mission in the country said Wednesday.

"A United Nations special report, which examines the impact on civilians of the United States' airstrikes on alleged drug-processing facilities on 5 May 2019 in Afghanistan, determines that the operation caused a large number of civilian casualties," UN Assistance Mission in Afghanistan (UNAMA) said in a statement.

The strikes were conducted in Bakwa district of western Farah province and in parts of the neighboring Delaram district of Nimroz province.

"Moreover, the UN is working to verify credible reports of at least 37 additional civilian casualties, the majority of whom were women and children," according to the statement, referring to separate airstrikes.

In 2018, some 6,400 tons of opium were produced in Afghanistan, a country notorious for growing opium-producing poppies for the illicit drug trade. Much of the opium is produced in western and southern parts of the country, in areas where Afghan security forces have little presence.

Some poor Afghan villagers work in narcotic-drug facilities as daily labor in remote areas to earn a living.