context: A few years after the First Crusade, in 1107, the Normans under the command of Bohemond, Robert's son, landed in Valona and besieged Dyrrachium using the most sophisticated military equipment of the time, but to no avail. Meanwhile, they occupied Petrela, the citadel of Mili at the banks of the river Deabolis, Gllavenica (Ballsh), Kanina and Jericho. This time, the Albanians sided with the Normans, dissatisfied by the heavy taxes the Byzantines had imposed upon them. With their help, the Normans secured the Arbanon passes and opened their way to Dibra. The lack of supplies, disease and Byzantine resistance forced Bohemond to retreat from his campaign and sign a peace treaty with the Byzantines in the city of Deabolis.
question: Who, between the Normans and Albanians, did NOT occupy Petrela?