The incident took place yesterday around 5 pm as Afghan security forces were clearing a village of Taliban elements, Salam Afghan, Helmand police spokesman, told AFP.
"In the strike, 16 Afghan policemen were killed including two commanders. Two other policemen were wounded," he said.
Omar Zwak, Helmand provincial governor spokesman, confirmed the strike and gave the same account.
It occurred in Gereshk district in Helmand, large parts of which are under Taliban control.
NATO's mission in Afghanistan issued a statement.
Also Read
"During a US-supported (Afghan security) operation, aerial fires resulted in the deaths of the friendly Afghan forces who were gathered in a compound," it said.
The US is the only foreign force in the coalition conducting airstrikes in Afghanistan.
Acting interior ministry spokesman Najeeb Danish gave a lower death toll than the provincial officials.
"The toll we have received is that unfortunately as a result of the strike, we have 12 police forces martyred and no one wounded," Danish told AFP.
He said a ministry delegation had been sent to the area to investigate the incident and help families of the victims.
In February, a US airstrike in Sangin killed at least 18 civilians, mostly women and children.
Last November 32 Afghan civilians were killed in a US airstrike in the northeastern province of Kunduz.
In October 2015, a US air strike during fighting hit a hospital operated by Medecins Sans Frontieres, killing 42 people and sparking international outrage.
Disclaimer: No Business Standard Journalist was involved in creation of this content