Two so-called insider attacks, in which a soldier in an Afghan National Army uniform turns his weapon on foreign troops, in as many weeks have killed three USA soldiers and wounded another seven.
Several US military personnel were wounded and evacuated after an apparent insider attack Saturday by an Afghan soldier in northern Afghanistan.
The attack was reportedly by an afghan Soldier and it is termed as a insider act.
The incident took place at Afghan National Army's (ANA) Shaheen Corps in Mazar-e Sharif city of Balkh province.
A coalition official told CNN that some USA military personnel were wounded and evacuated after what appears to be an insider or "green-on-blue" attack by an Afghan soldier.
In a separate statement, a US official said four USA military personnel were wounded. One other Afghan soldier was wounded.
On June 11, the insurgents claimed responsibility for a similar attack in which an Afghan soldier killed three United States soldiers and wounded a fourth in the eastern province of Nangarhar. The Taliban claimed responsibility for that attack, which unfolded on June 10 in eastern Afghanistan.
The suicide assault, or coordinated attack using one or more suicide bombers and an assault team, is a tactic frequently used by the Taliban, the Haqqani Network, al Qaeda and its branches. Earlier this year in March a similar insider attack wounded three U.S. soldiers at an Afghan military complex in Helmand province.
The attacker was shot and killed and one Afghan soldier was wounded. He had initially announced that three U.S. soldiers had been wounded.
In addition to the dead, nine police officers and nine civilians were wounded, he said.
"We have an enemy who is actively trying to drive a wedge between us", Operation Resolute Support said in a statement. But the emergence of an affiliate of the Islamic State group has created a sense of urgency to turn the war around.
US Defence Secretary Jim Mattis said on Monday he would present options on Afghanistan to President Donald Trump "very soon".
The Pentagon is set to announce it is sending another 4,000 USA troops to the country to counter the insurgents.