The fresh attack into the Mediterranean coastal city of Sirte contrasted with a stalemate in the mountain enclave of Bani Walid where demoralized anti-Gadhafi forces tried to regroup after being beaten back by loyalist snipers and gunners holding strategic high ground.

Intense resistance has stalled forces of Libya's new leadership trying to crush the dug-in fighters loyal to Gadhafi, weeks after the former rebels swept into Tripoli on Aug. 21 and pushed the country's leader out of power and into hiding. Sirte and Bani Walid are the main bastions of backers of the old regime in Libya's coastal plain, but smaller holdouts remain in the deserts of the center of the country — and another major stronghold, Sabha, lies in the deep south.

The resistance has raised fears of a protracted insurgency of the sort that has played out in Iraq and Afghanistan, even as the transitional government tries to establish its authority and move toward eventual elections.

A military spokesman for the transitional government said revolutionaries do not know Gadhafi's location.