Residents of northern Mali's largest city reported prolonged gunfire Sunday as the military carried out what it called a "clean-up" operation after Islamist militants claimed an attack on an army camp. "We're currently carrying out a clean-up to dislodge any Islamists that may have infiltrated" the city of Gao, said a Malian military source. "Some individuals fired three AK-47 shots at a Malian military camp in Gao overnight," the source added. "Our men responded forcefully. We see it as a very minimal incident. You can't even call it an attack." But "attack" was the word used by radical Islamist group the Movement for Oneness and Jihad in West Africa (MUJAO). "Saturday at midnight, nine mujahedeen arrived in Gao. They attacked the Malian army camp in Gao itself. The mujahedeen are going to continue fighting until the final victory," said Oumar Wahab, a MUJAO leader who was one of the city's rulers during the months that Al-Qaeda-linked groups controlled northern Mali, implementing a harsh version of Islamic law. The Islamist militants were chased from Gao in January by a French-led military operation to reclaim Mali's vast desert north after a 10-month occupation. The city was hit by several suicide bombings and guerrilla attacks in the following weeks, and Islamist fighters have continued to clash with French and African forces in the surrounding area.