Libyan revolutionary forces claimed to have captured parts of a sprawling convention center that loyalists of Moammar Gadhafi have used as their main base in the ousted leader's hometown and were shelling the city to try to rout snipers from rooftops in their offensive aimed at crushing this key bastion of the old regime.
The inability to take Sirte, the most important remaining stronghold of Gadhafi supporters, more than six weeks after the capital fell has stalled efforts by Libya's new leaders to set a timeline for elections and move forward with a transition to democracy.
Gadhafi supporters also hold the enclave of Bani Walid, where revolutionary forces have been stymied by a challenging terrain. But the transitional leadership has said it will declare liberation after Sirte's capture because that will mean it holds all of the seaports and harbors in the oil-rich Mediterranean coastal country.
British Defense Secretary Liam Fox pledged to keep up NATO airstrikes even after Sirte's fall, saying the international military action would continue as long as the remnants of the regime pose a risk to the people of Libya.