BAGHDAD: Iraqi forces said yesterday they face a tough battle against the Islamic State group in deep gorges and other natural hideouts in the western desert along the Syrian border, their last bastion in Iraq. "Our units have cleared 50 percent of the total area of the desert of around 29,000 square kilometers. The first phase is over," General Yahya Rassoul, spokesman of the Joint Operations Command said. "Now our units will proceed to clearing the rest of the desert zones, including Wadi (valley) Hauran," he said. "The valley is deep and reaches Syrian territory. The mission is to destroy all the hideouts in the desert and valleys to secure western Iraq's border with Syria" before soldiers are posted along the frontier, he said. Wadi Hauran, with 200-metre-deep (650-foot-deep) gorges, is the longest valley in Iraq, stretching 350 kilometers from the Saudi border to the Euphrates River, also reaching the frontier with Jordan.