Yemen\'s main oil export pipeline was blown up in the country\'s northeastern province of Marib, only a week after it was repaired from previous attacks, local police officials and witnesses said Thursday. The attack, the second of its kind in two weeks, hit the pipeline in Serwah district in Marib on Wednesday night, causing the flow to halt, a police official told Xinhua by phone on condition of anonymity. Thick smoke could be seen several miles away, witnesses said, adding that heavy clashes were heard following the bombing near a military site guarding the pipeline. Police blamed the attack on armed tribesmen. The pipeline carries about 110,000 barrels of crude oil per day from Marib province to an export terminal on the Red Sea. Yemen\'s oil and gas pipelines, as well as the country\'s main electricity grid, have been frequently attacked since the eruption of protests against former President Ali Abdullah Saleh in 2011. Oil revenues make up more than 70 percent of the state budget, while oil and gas products account for over 90 percent of Yemen\'s exports. Yemen\'s oil production rapidly declined from more than 400,000 barrels per day at the beginning of the past decade to the current 270,000 barrels per day.