ADEN (AFP/Reuters) - Yemeni army troops have killed 30 'Al-Qaeda fighters in a clash in southern Abyan province, including a leading member of the militant network, the defence ministry said Tuesday. The militants were killed in "fierce fighting that lasted more than three hours" on the outskirts of the city of Zinjibar, which is held by suspected Al-Qaeda gunmen, the ministry website said. It said that Hassan al-Aqili, described as a leading member of the Al-Qaeda in the northern region of Marib, was killed in the confrontation. Military and medics said earlier on Tuesday that 15 people, including nine soldiers, were killed in clashes overnight as army advanced to Zinjibar. Gunmen seized control of much of Zinjibar in late May. Security officials said the militants were Al-Qaeda fighters but the political opposition accused the government of embattled President Ali Abdullah Saleh of inventing a jihadist threat in a bid to head off Western pressure on his 33-year rule. Inside the city, only the base of the 25th mechanised brigade remains in govt hands. Scores of soldiers have been killed in clashes in and around Zinjibar. Yemen is the home of Al-Qaeda in the Arabian Peninsula, an affiliate of the slain Osama bin Laden's militant network. The group is blamed for anti-US plots including trying to blow up a US-bound airplane on Christmas Day in 2009. Saleh left for Saudi Arabia at the weekend for surgery on wounds suffered in an attack on his palace in Sanaa -- an absence that could be an opportunity to ease him out of office after nearly 33 years ruling the impoverished Arab nation. Global powers worry that chaos would make it easier for the Yemen-based wing of al Qaeda to operate and would multiply risks for neighbouring Saudi Arabia and other Gulf oil producers. "We are calling for a peaceful and orderly transition," US Secretary of State Hillary Clinton said Monday, adding that this would be in the best interests of the Yemeni people. Yemen's acting leader, Vice President Abu-Rabbu Mansour Hadi, said Saleh would return within days, but the position of Saudi Arabia, which has traditionally played an influential role in Yemeni politics, could now be decisive. Saudi officials say it is up to Saleh whether he returns home or not, but they, and Western powers, may want to revive a Gulf-brokered transition deal under which the Yemeni leader would have quit in return for immunity from prosecution.