Interim government forces set up checkpoints around Gaddafi stronghold and hope to take control by Monday or Tuesday Libya’s revolutionary fighters have stepped up attempts to capture the city of Sirte, reinforcing their siege of Muammar Gaddafi’s stronghold in an effort to place maximum pressure on those inside who are loyal to the deposed dictator. Interim government forces set up new roadblocks and checkpoints and posted snipers at strategic locations on Sunday, a day after mounting a big push that reportedly saw them enter the city from both east and west and come within a mile of the centre. The breakthrough came at a heavy cost, with seven rebel fighters dead and 145 wounded in fierce battles. Commanders said it was their intention to finally take Sirte on Sunday, but admitted that Monday or Tuesday might be more realistic. The biggest rebel brigade in Misrata, Halbus, was to be thrown into battle after returning to Sirte from the newly captured towns of Hun and Waddan further south. Nato was also keeping up its assault on Sirte, hitting four targets in pre-dawn air strikes. Despite overthrowing Gaddafi’s regime last month, the National Transitional Council (NTC) has not been able to take control of all of Libya. Sirte, birthplace of Gaddafi, as well as Bani Walid and pockets in the south of the country, have remained in the hands of loyalists to the old regime. It is not known whether Gaddafi is in Sirte but, even if he is not, capturing the town would be of immense symbolic value to the NTC. There are rising concerns over the humanitarian situation in the city, which is believed to be rapidly deteriorating. Nato has warned that Gaddafi forces are endangering “hundreds of families” . “Among the reports emerging from Sirte are executions, hostage-taking and the calculated targeting of individuals, families and communities within the city,” it said in a statement. On Saturday, the BBC reported , the transitional authorities came closer than ever to victory when troops entered the city after weeks of deadlock and advanced far along the road to the centre. But after coming under sustained fire from pro-Gaddafi fighters, the forces withdrew and regrouped overnight. Unconfirmed reports said the forces had been ordered to leave Sirte by Nato. An NTC fighter, El-Tohamy Abuzein, said snipers had fired on him and fellow fighters from mosques and other buildings. “They’re using the houses and public buildings,” he told Reuters. Helicopters ferried the injured to a hospital in Misrata which was so overwhelmed that surgeons had to carry out operations in corridors. Loudspeaker trucks broadcasting Islamic chants toured the city to give comfort to the bereaved. Libya Muammar Gaddafi Arab and Middle East unrest Middle East Africa Lizzy Davies Chris Stephen guardian.co.uk