Details of the attack remain murky, and members of the patrol have given conflicting accounts of it. It is unclear whether the patrol was simply ambushed, or whether it was attacked after the troops were reassigned to support a separate, clandestine counterterrorism mission against Islamist militants in the area.
Aid workers and tourists have long been urged to avoid the area where the attack occurred, near Niger’s border with Mali, because of the presence of both Al Qaeda- and Islamic State-affiliated groups.
In its statement sent to the website, Mr. Sahraoui’s group also claimed responsibility for an attack on a convoy of French troops in Mali on Thursday, which the French military said wounded three soldiers, according to Reuters.
The extent of Mr. Sahraoui’s ties with the Islamic State is unclear. The website in Mauritania that carried the group’s statement on Friday is an outlet favored by Mr. Sahraoui’s former colleagues in Al Qaeda, not by the Islamic State. The area in which Mr. Sahraoui’s group operates contains some of the most forbidding terrain on the planet, a landscape of undulating dunes where cellphone towers are few and far between.
“There is a lot we don’t know about how his operation connects back to the mother ship — what’s the connective tissue?” said Thomas Joscelyn, an analyst who has tracked the group for years as a senior fellow at the Foundation for Defense of Democracies in Washington. “There are a lot of possibilities and many factors in play.”
The remoteness of the area in which Mr. Sahraoui’s group operates, and the difficulty of getting reliable cellphone signals or internet access, could be one factor to explain the delay in releasing the statement. Another possibility is that the Islamic State’s media apparatus was disrupted after the group lost nearly 98 percent of its territory in Iraq and Syria.
Additionally, there have been reports of unrest among from Al Qaeda loyalists after Mr. Sahraoui…