According to the local security officials, the airstrike was carried out late on Wednesday afternoon in Siagerd district.
The officials further added that 8 Taliban insurgents including a commander of the group were killed and several others were wounded in the airstrike.
According to the officials, the militants were planning attacks during the gathering when they were targeted.
The Taliban militants group has not commented regarding the report so far.
The US forces in Afghanistan have stepped up airstrikes against the militant groups during the recent months.
The Obama administration granted broader role to the US forces based in Afghanistan to target the loyalists of the Islamic State of Iraq and Syria (ISIS) terrorist group as well as the Taliban militants.
The broader role was granted amid deteriorating security situation in the country and following concerns that the militant groups are attempting to expand insurgency in the country.