District governor Mohammad Rahim Amin said the North Atlantic Treaty Organisation air strike was “likely a mistake, due to bad co-ordination” in an area where Taliban insurgents are highly active.
A USA military official, said that he was aware of the Monday morning’s incident, which he said is “under investigation”.
Five other troops were injured, Mr Razaq added.
Daud Ahmadi, the police chief of Logar, said the airstrike “was caused by a coordination failure, and it resulted in the targeting of an Afghan National Army outpost in the district”.
Following the attack, an Afghan army convoy dispatched to the site was ambushed several times on its way by Taliban militants, but they managed to retrieve the dead bodies without any further casualties, Amin said.
Last week Mullah Mohammed Omar, Afghan Taliban leader backed peace talks with the government.
The Afghan Defense Ministry confirmed the incident, saying: “We have contacted the NATO-led forces to investigate the issue” but the USA forces were not available to comment.
Afghan officials said as many as 10 may have been killed in the apparent “friendly fire” incident, but initial casualty estimates varied widely.
It is rare for USA or coalition bombings to kill Afghan troops, but it has happened before.
Although there is also a report that the Afghan army does have some attack helicopters.
In June previous year, five US Special Forces operatives, an Afghan soldier and an interpreter were killed by a B-1 Lancer bomber’s misdirected payload in Zabul province.
In January, Afghan soldiers accidentally fired mortars at a wedding party that killed 17 women and children in the southern province of Helmand.