The twelve member Green Beret-led team that was ambushed by militants in Niger earlier this month became separated during the firefight and attempted to mount a counterattack, US officials told CNN Friday.
The two groups also lost contact with one another during the battle, likely adding to the confusion surrounding the engagement, one of the officials said.
The squad was travelling with 30 Nigerien soldiers when they were attacked by approximately 50 ISIS-affiliated fighters armed with rocket-propelled grenades, mortars, and heavy machine guns, according to US military officials.
In the subsequent gun battle, which lasted for hours, four US soldiers were killed and two were wounded.
Their Nigerien interpreter and four Nigerien soldiers were also killed. US-Nigerien forces managed to kill 20 militants during the fight on October 4 using primarily small arms.