In an unprecedented move, Sudan's parliament Monday voted unanimously to brand the government of South Sudan an enemy, after southern troops invaded the north's main oilfield. “The government of South Sudan is an enemy and all Sudanese state agencies have to treat her accordingly,” the parliament's resolution said. After the vote, Speaker Ahmed Ibrahim El-Tahir called in the legislature for the overthrow of the Sudan People's Liberation Movement (SPLM) which rules the South. “We announce that we will clash with SPLM until we end her government of South Sudan. We collect all our resources to reach this goal,” he said. World powers have urged restraint after heavy fighting began with waves of aerial bombardment hitting the South, whose troops last Tuesday seized Khartoum's main Heglig oil region from Khartoum's army. It is the most serious fighting since July 2011 when South Sudan separated after an overwhelming “yes” vote under a peace deal that ended 22 years of civil war. When the South became independent, Khartoum lost about 75 percent of its oil production and billions of dollars in revenue, leaving the Heglig area as its main oil center. Tuesday's attack caused a total production shutdown, said Ahmed Haroun, Governor of South Kordofan. The latest fighting follows clashes around Heglig that began on March 26. South Sudan disputes that Heglig is part of the north's territory. Col. Philip Aguer, Southern army spokesman, said the aerial attacks over Heglig also seriously wounded nine people and hit oil wells. He also said that the town of Bentiu in South Sudan's Unity State was hit and that the conflict has spread to several southern states bordering Sudan, including Western Bahr El Ghazal. “There has been continued bombardment by Sudan Armed Forces,” Aguer said. “Our forces are now on maximum alert.”