 At the same time, Euphemius began to regret his alliance with the Aghlabids, and opened secret contacts with the imperials, urging them to resist the Arabs.The Muslims recommenced their advance soon after, and laid siege to the city.Byzantium, which at the same time was forced to face a threat much closer to home at Crete, was unable to send much aid to the beleaguered island, while the Muslims received reinforcements from Africa.