"Five Al-Qaeda fighters were killed and several others wounded in the late Monday bombardment of Al-Quz," on the outskirts of the provincial capital Zinjibar, which the militants overran last May, the official said.

Troops and militants traded machinegun fire early on Tuesday on the city's northern and eastern outskirts, said the official from nearby Jaar -- another militant stronghold.

Al-Qaeda militants have exploited the weakening of the central government in Sanaa in the face of 10 months of deadly protests last year to strengthen their presence, especially in the south and east.