A US military vehicle was stormed by an improvised explosive device in Niger, at the site of a deadly extremist assault on American forces in 2017, the military announced on Sunday.

The Mine Resistant Ambush Protected All-Terrain Vehicle activated the bomb “while entering a firing range in the vicinity of Ouallam, Niger on June 8, 2019” during a joint training exercise, US Africa Command said in a statement.

“There are no reported US casualties, however, as a precaution, US service members are being evaluated,” it said, adding that Nigerien forces had secured the scene of the blast.

Four American troop members and four Nigerien troop members were murdered in an October 2017 ambuscade in the country, when scores of extremists overran their convoy in southwestern Niger, near the border with Mali.

The ambuscade claimed the largest number of American lives in combat anywhere in sub-Saharan Africa since the “Black Hawk Down” scene in Somalia in 1993.

Niger is one of a number of poor, fragile countries in the Sahel region that have been stormed by an extremist revolt.

Various terrorists groups operate in the country’s west and north, and Nigeria’s Boko Haram is present in its southeast.

The country is part of the so-called G5 Sahel group set up to manage a coordinated response to the extremist insurgency.