The Carthaginian army, under Hasdrubal, encamped on the other side of the lake near the fortress of Nepheris, whence it obstructed the labours of the Roman soldiers despatched to cut timber for constructing machines, and the able cavalry-leader in particular, Himilco Phameas, slew many of the Romans.

Censorinus fitted up two large battering-rams on the tongue, and made a breach with them at this weakest place of the wall; but, as evening had set in, the assault had to be postponed.

During the night the besieged succeeded in filling up a great part of the breach, and in so damaging the Roman machines by a sortie that they could not work next day.

Nevertheless the Romans ventured on the assault; but they found the breach and the portions of the wall and houses in the neighbourhood so strongly occupied, and advanced with such imprudence, that they were repulsed with severe loss and would have suffered still greater damage, had not the military tribune Scipio Aemilianus, foreseeing the issue of the foolhardy attack, kept together his men in front of the walls and with them intercepted the fugitives.
Manilius accomplished still less against the impregnable wall of the citadel.

The siege thus lingered on.