Fighting intensified in south Yemen on Monday as the army bombarded alleged Al-Qaeda fighters who appear to have seized control of the city of Loder while civilians fled.
Authorities said that Adel Saleh Hardaba, 27, who they described as the Al-Qaeda second-in-command in the southern city of Loder, was killed in renewed fighting on Monday.
Loder, in the he Abyan Province, has been gripped by deadly clashes since Friday.
"The army is imposing a tight siege on the city, chasing out Al-Qaeda militants and collaborating gunmen," a security official said, adding that the military had shelled houses used by militants as launchpads for attacks.
He said that many of the militants holed in the city are believed to be foreigners, notably Saudis and Pakistanis.
Another security official told AFP that civilians have fled the city where "only gunmen are left."
At least 29 people, including 11 soldiers, have been killed in clashes which erupted on Friday in Loder. Seven alleged Qaeda militants were killed Sunday, while seven others were killed on Friday.
Witnesses have said that fighting has intensified since Sunday night, after an ultimatum to militants to surrender expired.
Khaled Muftah, who escaped with his family of 11, told AFP by telephone that the army was bombing the city "indiscriminately," while many Al-Qaeda gunmen were seen flowing into Loder and taking up positions.
The army had distributed pamphlets urging civilians in Loder, which has a population of 80,000, to leave, while Defence Minister General Mohammed Nasser was in the city on Sunday to supervise operations.
South Yemen, and Abyan province in particular, is feared to have become a base for Al-Qaeda militants to regroup under the network's local franchise, Al-Qaeda in the Arabian Peninsula (AQAP).
Largely tribal Yemen is the ancestral homeland of Osama bin Laden.
The country is also under a constant threat of a renewed war in the north, where a fragile truce between the army and Shiite Huthi rebels since February has been shaken by sporadic clashes between rebels and government-backed tribes.
Five rebels and four tribesmen were killed in clashes on Monday in the Amran province town of Huth, halfway between the capital and the city of Saada, a rebels' stronghold.
The shootout erupted when rebels entered the town to offer condolences to the family of a fellow Huthi killed by a supporter of the pro-government prominent tribal chief Sheikh Hussein al-Ahmar.
Ahmar, who on August 1 mediated the release of 100 Yemeni soldiers captured by Huthis in recent fighting, had ordered tribesmen to kill any Shiite rebel entering Huth, according to a source close to the rebels.
The rebels and the army engaged in deadly fighting in July that lasted nine days, rattling an already fragile February truce which had ended a six-month round of fighting in a conflict that started in 2004.
The Shiite rebels complain of political, social and religious marginalisation, and have repeatedly fought with government forces in a conflict that has killed thousands and displaced some 250,000 people.