Jan. 13 (UPI) -- An Islamic State affiliate has claimed responsibility for an attack three months ago in Niger that killed four American soldiers on patrol with Nigerien troops.
"We declare our responsibility for the attack on the U.S. commandos last October in the Tongo Tongo region of Niger," said the statement, attributed to Adnan Abu Walid al-Sahraoui, who was a member of Al Qaeda's regional branch before pledging allegiance to the Islamic State in 2015.
The statement was issued to Nouakchott News Agency, a website in Mauritania that has previous received statements from extremist militants.
The statement didn't explain why it took so long to claim responsibility after the Oct. 4 assault. American officials had said the group probably carried out the attack, which also five Nigerien soldiers.
It's not clear if patrol was ambushed, or whether it was attacked after the troops were reassigned to support a separate, clandestine counterterrorism mission against Islamist militants in the area.
The news agency also reported that the group has claimed responsibility for Thursday's attack on a French military convoy, as well as attacks in Niger and border areas with Mali and Burkina Faso.
"There is a lot we don't know about how his operation connects back to the mother ship -- what's the connective tissue?" Thomas Joscelyn, a senior fellow at the Foundation for Defense of Democracies in Washington told The New York Times. "There are a lot of possibilities and many factors in play."
Sahraoui's group operates in rough parts of the desert, where cellphone towers are scarce.
He got his start in Al-Qaida's branch in the region, which reported to Osama bin Laden through letters carried across the desert by couriers. He left Al-Qaida in 2012, after the jihadists seized most of northern Mali.
In May 2015, Sahraoui swore loyalty to the Islamic State leader, Abu Bakr al-Baghdadi, but his video pledge was not released by the group's news agency until October 2016.
Unrest has been reported among from Al-Qaida loyalists after Sahraoui made his pledge of allegiance to the Islamic State. "There were even reports at one point that he was injured in a shootout with Al Qaeda," Joscelyn said.