* Yemen army facing fierce challenge in Abyan
* Yemen in political limbo as president recuperates
* Yemen al Qaeda arm says its situation good, vows strikes (Adds al Qaeda statement)
By Mohammed Ghobari and Mohammed Mukhashaf
SANAA/ADEN, July 26 (Reuters) - Yemeni forces said on Tuesday they killed 10 al Qaeda militants who attacked their camp outside the southern town of Zinjibar, and the Islamist group vowed in an audio message to keep fighting.
The militants have posed a rising challenge in recent months to army control in southern Yemen, in areas that lie east of a shipping lane where 3 million barrels of oil pass daily.
They seized several areas in the province of Abyan, raising fears in the West and neighbouring Saudi Arabia that al Qaeda’s Yemen wing is expanding and taking advantage of political turmoil and six months of anti-government protests.
Al Qaeda in the Arabian Peninsula (AQAP) has yet to release any statements tying itself to the fighting in Abyan or confirming any deaths of its members in clashes there.
But on Tuesday it published an audio message addressed to global al Qaeda leader Ayman al-Zawahiri.
“Our situation is good, thank God, and we are progressing well on the local and international level, according to your plan,” the group’s leader Nasser al-Wuhayshi said in a voice recording posted on Islamist websites.
“We will not stand with our hands tied ... our war with the Zionist Crusader campaign continues, for they are the ones who chose war,” he said.
Reuters could not verify the authenticity of the tape but the voice sounded like that in previous recordings from the militant leader.
Yemen, rocked by daily protests against the rule of President Ali Abdullah Saleh, has been in a state of political limbo since Saleh flew to Riyadh for treatment following a bomb attack on his palace last month. He has vowed to return.
Saleh’s opponents accuse him of letting his forces ease their grip around areas suspected of hosting militants, in order to convince foreign governments that only he stands in the way of a militant takeover.
The army launched an offensive last week against militants in Abyan, but has so far only regained one military site. An army spokesman, speaking on condition of anonymity, said al Qaeda fighters attacked one of its camps on Monday night.
“The 10 militants were killed by heavy shells before they could make it to the military camp,” he said, adding that one of those killed was a senior member of the militant group.
Security analysts have suggested that many of those killed in recent weeks, which the government claimed were al Qaeda, are members of other militant groups operating in the south.
“It wouldn’t surprise me if there were puritanical militants who want to see closer adherence to what they consider to be Islamic values but didn’t necessarily share the trans national agenda of AQAP (al Qaeda’s Yemen wing),” said security analyst Jeremy Binnie, of IHS Jane’s.
The United States and Saudi Arabia, targets of foiled AQAP attacks, hoped to bring stability to Yemen by pushing Saleh into signing a Gulf-brokered transition plan, but he has backed out of inking the deal three times.
There have been repeated reports of suspected U.S. drone strikes on areas believed to harbour al Qaeda militants.
About 90,000 people have fled the violence in Abyan, most of them heading to the nearby port city of Aden, causing the army to deploy a security belt around the strategic coastal city out of fear of militant infiltration.
There have been two car bomb attacks in Aden in the past week. The first, last Thursday, targeted a British resident. The government blamed AQAP for a suicide attack that killed nine soldiers on Sunday. (Additional reporting by Firouz Sedarat in Dubai; Writing by Erika Solomon)