 In the meantime, another cavalry raid was dispatched against the region of Etna and was so successful that the price for Byzantine captives plummeted.In 837, a Muslim army under Abd al-Salam ibn Abd al-Wahhab attacked Enna, but was defeated by the Byzantines, and Abd al-Salam himself was taken prisoner.The Muslims responded by reinforcing their position around Enna, which they placed under siege.