TRIPOLI/ROME: Libya's top oil official became the latest leading figure to desert Muammar Gaddafi Wednesday, complaining of “unbearable” violence and adding political momentum to a revolt against the leader's long rule. The defection came as NATO extended its Libyan mission for a further 90 days, after Gaddafi made it clear he would not step down, dashing hopes of a negotiated end to the fighting. British Foreign Secretary, William Hague, said the move was an important reaffirmation of the international community's resolve and determination to ... protect the people of Libya. In rebel-held eastern Libya, an explosion damaged two cars outside Benghazi's Tibesti hotel, a building that has been used in the past for news conferences by the rebels seeking to topple Gaddafi, Arab television stations reported. There was no immediate word of what caused the blast, or of any injuries. The defection by National Oil Corp head Shokri Ghanem, who is also a former prime minister, came two days after the defections of eight army officers including five generals and those in earlier weeks of senior diplomats and former ministers. Speaking at a news conference in Rome organized by the Libyan ambassador, who has also defected, Ghanem said he had left his job because of the “unbearable” violence in Libya. Now in its fourth month, the Libyan conflict is deadlocked, with rebels unable to break out of their strongholds and advance towards Tripoli, where Gaddafi appears to be firmly entrenched. Rebels control the east of Libya around the city of Benghazi, the third-biggest city Misrata, and a mountain range stretching from the town of Zintan, 150 km south of Tripoli, toward the border with Tunisia. Meanwhile, after talks with Gaddafi, South African President Jacob Zuma said the Libyan leader had stated emphatically he would not leave Libya – making a negotiated end to the conflict impossible given rebel demands for his departure. Zuma was in Tripoli on Monday to try to revive an African “roadmap” for ending the conflict, which started in February with an uprising against Gaddafi and has since turned into a war in which thousands of people have been killed.