Local sources in the governorate of Mareb in Yemen confirmed to Arabstoday that tribal Yemenis bombed the main crude oil pipeline on Sunday night. The pipeline transfers oil from Mareb to the exporting port in Ras Essa in west Yemen on the Red Sea. The  same sources added: \"the main pipelines in Mareb exploded in two different places Sunday night in the area of Obayda valley.\" Sources believe that the attackers are the same ones who bombed it last June over a demand to release their prisoners from Yemeni authorities. The government has received another round of threats from tribal Yemenis. The incident is thought to have tried to complete unfinished business after the initial attack, which has now added pressure and problems for the Yemeni government. The inability to prevent the frequent attacks on gas and oil pipelines at Mareb and Shabwa governorates reflects negatively on the Yemeni economy. Military troops and security have been intensified along the pipeline areas, but the Yemeni economy is still experiencing one of its worst crises.