* Eighteen soldiers hurt in battle with jihadi militants
* Militants hit Ahwar army camp in turbulent Abyan province
* Qaeda's Yemen wing could threaten Saudi Arabia, oil routes
A suicide bomber killed at least five Yemeni soldiers on Friday in a suspected Islamist militant attack on a military base in the south of the country, a Yemeni military official said.
Militants linked to Al Qaeda in the Arabian Peninsula (AQAP) are increasingly targeting Yemeni army facilities in the U.S.-allied state, which shares a long border with Saudi Arabia, the world's top oil exporter, and flanks major shipping lanes.
The military official said the bomber drove a car laden with explosives and blew himself up at the gate of the army camp in Ahwar, an area in the southern province of Abyan.
Other militants attacked soldiers in the camp with machineguns and rocket-propelled grenades (RPGs), the source said, adding that 15 soldiers were wounded in the clashes.
The military official gave no detail on any casualties among the militants, but said the fighting was still going on.
Local witnesses said a helicopter, apparently belonging to the Yemeni army, was circling in the vicinity.
AQAP is regarded by the United States as one of the most active wings of the militant network, posing a serious threat to Western interests including oil tanker traffic in the Red Sea, the Gulf of Aden and the Arabian Sea.
Last month, dozens of militants stormed and captured the headquarters of the Yemeni army's Second Division in the eastern coastal city of al-Mukalla and seized some military personnel. Military officials said four Yemeni soldiers were killed and nine wounded in a counter-strike to retake the base.
AQAP said in a statement last week that the Sept. 30 attack targeted an operations room used by the United States to direct drone strikes against militants. This was denied by a Yemeni official, who said the facility contained a counter-piracy room for monitoring and securing shipping routes in the Arabian Sea.
Yemen's state news agency Saba reported on Thursday that a soldier was killed and two injured in militant attacks in al-Bayda province, south of the capital Sanaa. Saba said al Qaeda fighters suffered heavy losses wand were forced to flee, but provided no details.
Militants took advantage of political chaos in Yemen during the Arab Spring uprising in 2011 to seize control of some towns in the south of the impoverished Arabian Peninsula state.
They were subsequently beaten back by Yemeni armed forces, with assistance from the United States, and dispersed into smaller groups spread across the arid, rugged south.
But they have since carried out a series of attacks on important military and civilian targets, killing hundreds of soldiers and some senior officers, including Major General Salem Qatan, the Yemeni army commander in south Yemen.