BIN JAWWAD, Libya -- Rebel forces bore down yesterday on Moammar Gadhafi's hometown of Sirte, a key government stronghold where a brigade headed by one of the Libyan leader's sons was digging in to defend the city and setting the stage for a bloody and possibly decisive battle.
The opposition made new headway in its rapid advance westward through oil towns and along stretches of empty desert highway toward Sirte and beyond to the big prize -- the capital, Tripoli.
But the rebels remain woefully outgunned by Gadhafi's forces, who swept the insurgents from positions in eastern Libya until the international intervention forced government troops to withdraw.
Rebels acknowledged they could not have held their ground without international air and cruise missile strikes. Libya state television reported new NATO airstrikes after nightfall, targeting "military and civilian targets" in the cities of Garyan and Mizda, about 40 miles and 90 miles respectively from Tripoli.
NATO insisted that it was seeking only to protect civilians and not to give air cover to an opposition march. But that line looked set to become even more blurred. The airstrikes now are clearly enabling rebels bent on overthrowing Gadhafi to push toward the final line of defense on the road to the capital.
Vice Adm. William Gortney, staff director for the Joint Chiefs of Staff, said the United States was hitting Libyan targets with Thunderbolts and AC-130 gunships, aircraft that can fly low enough to support ground operations.
There was growing criticism from Russia and other countries that the international air campaign is overstepping the bounds of the UN resolution that authorized it.
The complaints came at a critical transition in the campaign from a U.S. to a NATO command. That threatens to hamper the operation, as some of the 28 NATO member nations plan to limit their participation to air patrols, rather than attacks on ground targets.