BAMAKO, Mali - A suicide bomber on a scooter attacked a Malian army patrol in the troubled northern city of Gao on Saturday as other militants in a car sprayed the troops with gunfire, sparking a clash that left three suspected militants and two soldiers dead, an official said.

The attack, in which four other soldiers were wounded, underscores the challenges facing the country following a French-led military intervention, which succeeded in liberating the three main towns occupied by the al-Qaida-linked groups in northern Mali. While the initial military campaign has succeeded in securing the largest population centers in the north, the extremists have found refuge in sparsely populated areas, from where they strike using roadside bombs and suicide attacks.

Lt. Col. Souleymane Maiga, head of public relations for the Malian army, told The Associated Press that a unit of Malian soldiers was on patrol at around 1:30 p.m. near the village of Amakouladji, about 30 miles north of Gao, when they spotted a suspicious man on a scooter and stopped him. While they were searching him, a car surged forward, and began spraying the troops with machine gunfire.

"That was when the jihadist on the motorcycle set off the bomb that he was wearing," Maiga said.

France sent about 4,000 troops to Mali in January after the jihadists, who had already taken over a territory as large as France itself, began pushing south.