Yemen resumed pumping crude oil through its main export pipeline on Thursday, an oil official said, after repairs took place under army protection and seven people were killed in brief clashes between solders and tribesmen. Tribesmen on July 12 blew up the pipeline in the Serwah area of the central Maarib province, halting crude flows and disrupting a main source of revenue for the impoverished state. The Defence Ministry’s September 26 website reported on Wednesday that five government soldiers and two tribesmen were killed in clashes, which erupted when troops fought off armed tribesmen blocking a road leading to the site. Engineers, working under army guard, managed to repair the pipeline, the website reported. A local oil official told Reuters that pumping resumed on Thursday. Yemen’s oil and gas pipelines have repeatedly been sabotaged by insurgents or tribesmen since anti-government protests led to a power vacuum in 2011, causing fuel shortages and slashing export earnings. The government relies on crude exports to bolster foreign currency reserves and finance up to 70 percent of its spending. The Maarib pipeline carries around 70,000-110,000 barrels per day of Marib light crude from the Safer oilfields to the Ras Isa oil terminal on the Red Sea, the officials said. It was repaired in late May after a previous attack by tribesmen. Disgruntled tribesmen carry out such assaults to pressure the government to provide jobs, settle land disputes, or free relatives from prison. Lawlessness in Yemen is a global concern - particularly for the United States and its Gulf Arab allies - because of its strategic position next to oil exporter Saudi Arabia and shipping lanes, and because it is home to one of al Qaeda’s most active groups. Yemen is struggling to restore state authority after long-serving President Ali Abdullah Saleh was forced to step down in 2011.