In 1997, Algeria was at the peak of a civil conflict that had begun after the military's cancellation of 1992 elections set to be won by the Islamic Salvation Front (FIS).
Larbaa was a major center for the FIS's armed wing, the Islamic Salvation Army (AIS), which the GIA had recently declared war on; Mustapha Kartali, a former GIA chief who had split from him in 1995 and become head of the AIS's Katibat Errahamane brigade, was based in the area.
That night, a number of guerrillas armed with shotguns, knives, and sabres (30 according to The Economist, 100 according to Liberte) stormed into the area by night and started breaking into homes and cutting the residents' throats, killing men, women, and babies, and burning some victims alive.
According to Robert Moore of The Observer as quoted by Ahmed Bouzid in Zmag: "in the village of Larbaa the attack took place 300 yards from a large barracks."
The New York Times confirms that "the electricity had been cut in the town before the assault and the attack occurred close to an army barracks" (Roger Cohen, "Despite freeing of a militant, no letup in Algerian strife", The New York Times, 2 August 1997, as cited by Algeria-Watch).