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STORY: Libyan government forces said on Tuesday they believed they had one of Muammar Gaddafi's sons cornered in the center of the deposed leader's home town, but determined resistance was keeping them at bay.
After weeks of fighting, National Transitional Council (NTC) forces have taken most of Sirte and driven Gaddafi loyalists into two northern neighbourhoods near the Mediterranean shore.
Capturing the city, which Gaddafi had turned into a showcase second capital, will consolidate the NTC's control in Libya and allow it to focus on rebuilding the country, but international concern about civilians caught up in the fighting has mounted.
One NTC commander said Gaddafi fighters were defending their last two districts in Sirte tenaciously because Mo'tassim Gaddafi, his father's national security adviser, was with them.
The fighting on Tuesday focused on Omar al-Mokhtar street, a tree-lined thoroughfare in a well-heeled neighbourhood.
Muammar Gaddafi himself is not in Sirte, according to NTC officials coordinating the hunt for him, but is instead believed to be far to the south in the Sahara desert.
With Libya's new rulers focused on the bruising battles for Sirte and Bani Walid, another pro-Gaddafi town, a political vacuum has emerged. There is no formal government and the process of holding elections is on hold.
Armed anti-Gaddafi factions from different regions are vying for power, complicating the NTC's task of asserting national control in the oil-exporting nation of six million people.