Forces loyal to Libyan leader Col Muammar Gaddafi have launched further air strikes on the rebel-held oil port of Ras Lanuf, in a renewed offensive. Warplanes fired missiles on residential areas and near rebel positions. Intense shelling and the deployment of heavy armour has been reported, but there were no reports of casualties. Meanwhile, the rebels said they had been approached by pro-Gaddafi officials offering to hold talks on an exit for the Libyan leader. The rebels rejected the offer, a spokesman said. Heavy shelling is reported.