In late summer 251 BCE the Carthaginian commander Hasdrubal – who had faced Regulus in Africa – hearing that one consul had left Sicily for the winter with half of the Roman army, advanced on Panormus and devastated the countryside. The Roman army, which had been dispersed to gather the harvest, withdrew into Panormus. Hasdrubal boldly advanced most of his army, including the elephants, towards the city walls. The Roman commander Lucius Caecilius Metellus sent out skirmishers to harass the Carthaginians, keeping them constantly supplied with javelins from the stocks within the city. The ground was covered with earthworks constructed during the Roman siege, making it difficult for the elephants to advance. Peppered with missiles and unable to retaliate, the elephants fled through the Carthaginian infantry behind them. Metallus had opportunistically moved a large force to the Carthaginian's left flank, and they charged into their disordered opponents. The Carthaginians fled; Metellus captured ten elephants but did not permit a pursuit. Contemporary accounts do not report either side's losses, and modern historians consider later claims of 20,000–30,000 Carthaginian casualties improbable.