Staff remove damaged items following a bomb explosion at a police station by unknown assailants in Benghazi, Sunday. Two more police stations were attacked in Libya's eastern city in the early hours of Sunday morning, the local council said, after two others were bombed on Friday. — Reuters Jessica Donati TRIPOLI — Gunmen have ended a siege of Libya's foreign and justice ministries but the two-week standoff has left many unresolved questions about the government's ability to impose its authority in the capital, let alone the restive east of the country. The episode heightened security concerns that prompted oil group BP, one of the biggest foreign companies active in Libya, to announce on Sunday it was withdrawing an unspecified number of employees from Tripoli. The US and British governments had already pulled out some diplomats temporarily. In a separate development, two more police stations were attacked in Libya's eastern city of Benghazi in the early hours of Sunday, the local council said. The suspected grenade attacks caused “small explosions” but no damage or casualties, and followed bomb blasts outside two other stations on Friday. More than 18 months after the fall of dictator Muammar Gaddafi, Libya's new rulers have yet to impose a firm grip on a country awash with weapons. Rebel groups that helped to overthrow him are still refusing to disband, and remain more visible on the streets than the state security forces. The siege of the Tripoli ministries was launched on April 28 by self-styled ‘revolutionaries' demanding a law to ban anyone who held a senior position under Gaddafi from serving in the new administration. Parliament bowed to the demand and approved the legislation a week later, despite criticism from rights groups and diplomats who said it was sweeping, unfair and could cripple the government. Justice Minister Salah Marghani denied there had been any deal with the gunmen who left the ministries late Saturday. They have also demanded the resignation of Prime Minister Ali Zidan. “I am not aware of any deal, they just left and they have handed over the place back... they left a bouquet of flowers,” he said in an interview with Radio France Internationale. Ahmadi Al Deli, head of a committee including members of parliament which had negotiated with the gunmen, denied any agreement to let them set up an office inside the Foreign Ministry. He said certain “unacceptable” requests, like access to the ministry's secret archives, had also been rejected. A political risk consultant said the outcome was likely to encourage armed groups to pursue demands by force. “What is clear is that sieges and the implicit or explicit threat of force delivers results. So it is likely that armed groups will continue to flex their muscles to achieve their political objectives in the medium term at least,” said Anthony Skinner, Middle East and North Africa director at risk consultancy Maplecroft. Outside the Foreign Ministry late Saturday, the revolutionaries had been replaced by a security force known as the Supreme Security Committee (SSC), made up of former rebel fighters now subordinate to the Interior Ministry. — Reuters