The town of Ajdabiya, 90 miles south of Benghazi, was firmly in government hands after most of its rebel defenders retreated under fire from a withering artillery barrage on Tuesday. Those who stayed had now handed over their guns, a rebel officer said.

The breakdown of rebel defenses in Ajdabiya, 480 miles southeast of Tripoli, threatened to open the gateway to the long stretch of eastern Libya that has been in the control of the opposition throughout the monthlong uprising. Its fall would allow regime forces to bombard Benghazi, Libya’s second largest city and the de facto capital of the opposition, by air, sea and land…

In Benghazi, seat of the insurgents’ provisional national council, the mood was a mixture of defiance and nervousness, with some citizens predicting a bloodbath and others confident the rebels would still snatch victory against the government offensive.