SANA'A/ADEN – A senior Yemeni army official was killed Saturday in an ambush by suspected Al-Qaeda members, while the army battled tribesmen who blew up the country's main oil export pipeline. The chief-of-staff for Yemen's central military region in turbulent Maarib province, home to a large portion of the impoverished country's oil, died when gunmen fired on his vehicle, a security official said. The attackers were probably militants linked to Al-Qaeda, said the official, who did not want to be identified. Yemeni troops also launched an offensive in Maarib after an attack on the principal oil pipeline there Friday. Two officers were killed and four soldiers injured in clashes with tribesmen, according to another security official. Repairs had begun on the Maarib oil pipeline and power lines just last week after the government reached a deal with tribesmen to stop attacking infrastructure. Yemen's oil and gas pipelines have been repeatedly sabotaged by militants or tribesmen since anti-government protests created a power vacuum in 2011, causing fuel shortages and slashing export earnings. The 430-km pipeline used to carry 110,000 barrels per day from Maarib oil fields in the centre of the country to the Ras Isa export terminal on the Red Sea. Yemen has struggled to restore normality since President Abdbabbuh Mansour Hadi was elected in February following a year of protests that forced his predecessor Ali Abdullah Saleh to step down after 33 years in power. Security forces also foiled a car bomb targetting the director for security operations in the eastern province of Hadramout Saturday, a third local official said on condition of anonymity. – Reuters