The bomber struck Najda Camp in the Abyan provincial capital of Zinjibar just 55 kilometres (33 miles) along the coast from second city Aden where the government has its headquarters.

According to the sources, He failed to get through the gate and heavy exchanges of fire ensued as other assailants tied to penetrate the base.

The explosives were concealed in the back of a pick-up truck under a pile of firewood, the sources said.

No group has claimed responsibility for the attack.

The radical militants have strengthened their presence, taking advantage of two years of fighting between government forces and Houthis who control large swathes of northern Yemen.

-Agencies