Witnesses say Moammar Gadhafi's forces have captured Zwara, the last rebel-held city west of Tripoli to fall back under government control.

Tuesday's victory solidifies Gadhafi's hold on the western stretch of coastline from the capital to the Tunisian border even as the Libyan leader advances against rebels in their eastern strongholds.

A cacophony of gunfire could be heard on the telephone Tuesday as army troops celebrated, but rebels promised to regroup and fight back.

Zwara was one of the first towns seized by the rebels as they made gains early in the monthlong uprising against Gadhafi's rule.

Rebels in Zwara say government troops retook the town after battering it with heavy tank and artillery fire, but sporadic street battles are ongoing.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

TOBRUK, Libya (AP) _ Rebels say they are fortifying the town of Ajdabiya against a possible assault by advancing forces loyal to Libya's longtime leader Moammar Gadhafi.

Rebel spokesman Ahmed al-Zwei said Tuesday that "intermittent" fighting between the two sides was taking place on a 50-mile (80-kilometer) stretch of road between Ajdabiya and the oil port of Brega. Control of Brega has been split between the rebels and regime forces after days of fierce clashes.

Recapturing Ajdabiya would give Gadhafi's forces a significant boost as they continue to reverse the string of rebels' military successes when they began a march from the opposition-held east of the country to the capital of Tripoli.