On June 4, 2005, militants from the Salafist Group for Preaching and Combat (GSPC) attacked a Mauritanian army barracks in Lemgheity, Mauritania.

[3] The jihadists had over 150 men according to post-battle estimates from the Mauritanian Army, and were commanded by Mokhtar Belmokhtar, Abderrahman al-Nigiri, and Abdellahi Ould Hmeida.

Other prominent jihadists such as Djamel Okacha, Jouleibib, and Khaled al-Barnaoui all participated in the Lemgheity attack as well.

Algerian militants in the group reacted harshly to the mufti's proposal, demanding all the soldiers be slaughtered.

The jihadists first took control of the barracks' communications post to prevent the soldiers for calling for reinforcements, and then surrounded the weapons depot.

The Lemgheity attack allowed the GSPC to reestablish itself as an international militant group and connect Abdelmalek Droukdel to senior al-Qaeda members, creating a pathway to the formation of Al-Qaeda in the Islamic Maghreb (AQIM) from the GSPC, which occurred in 2006.