Rebels in Libya are retreating from their former strongholds along the eastern coast as they come under fire from Col Muammar Gaddafi's forces. The rebels have now lost the key oil port of Ras Lanuf and the nearby town of Bin Jawad, and are also in full retreat from Brega. In the west, the rebel-held town of Misrata is still coming under attack from pro-Gaddafi troops, reports say. Britain's prime minister said arming rebels had not been ruled out. David Cameron's remarks echoed those made earlier by US President Barack Obama. Dramatic shift The BBC's Ben Brown, in Ajdabiya, said that the rebels are essentially now in retreat as they simply cannot compete with the discipline and fire-power of Col Gaddafi's forces. He says the current situation is a dramatic about-turn for the rebels who, over the weekend, had seized a string of towns along the coast and seemed to be making good progress. France and the US say they are sending envoys to the rebel-held city of Benghazi in the east to liaise with the interim administration there. And British Foreign Secretary William Hague said a UK diplomat met Libyan rebel leaders in Benghazi earlier this week. The UK has also made moves to expel five Libyan diplomats based in London, Mr Hague told MPs on Wednesday. Mr Obama told reporters on Tuesday that Col Gaddafi had been greatly weakened by the coalition air strikes and would ultimately step down. Mr Cameron said that the RAF had flown 24 sorties over Libya on Tuesday night which had destroyed artillery and an armoured vehicle near the strategic city of Sirte. Sirte is Col Gaddafi's birthplace and lies on Libya's northern coast, roughly half way between the capital Tripoli and Benghazi. On Tuesday, the Obama administration and British foreign secretary suggested the UN resolution authorising international action in Libya could also permit the supply of weapons. This message was reinforced by Mr Cameron in parliament on Wednesday. "UN [Security Council Resolution] 1973 allows all necessary measures to protect civilians and civilian-populated areas, and our view is this would not necessarily rule out the provision of assistance to those protecting civilians in certain circumstances," he said. "We do not rule it out, but we have not taken the decision to do so." But Russian Foreign Minister Sergei Lavrov denied UN resolution 1973 gave a mandate to arm the rebels. "The Nato Secretary General Fogh Rasmussen declared that the operation in Libya was being staged to protect the population and not to arm it - and here, we completely agree with the Nato secretary general," he said. In a separate development, an international conference on Libya in London has agreed to set up a contact group involving Arab governments to co-ordinate help for a post-Gaddafi Libya. Several thousand people have been killed and thousands wounded since the uprising against Col Gaddafi's rule began more than six weeks ago. Source: BBC