Less than two thousand militants related ISIS extremist groups are estimated to remain in the Syrian city of Raqqa, as they are fighting for their survival in the face of an offensive by the U.S.-backed Syrian Democratic Forces, said U.S Special Envoy for International Coalition Brett McGurk. He added that the Syrian Democratic Forces had cleared about 45 percent of Raqqa since launching an attack in early June to seize Islamic State's stronghold in northern Syria. Some 2,000 ISIS fighters are left in the city and "most likely will die in Raqqa," he said. The assault on Raqqa coincided with the final stages of a campaign to drive Islamic State from the Iraqi city of Mosul, where the Islamist militants were defeated last month. McGurk said Islamic State has lost 27,000 square miles (70,000 sq km) of the territory it once held in the two countries - 78 percent of what they had seized in Iraq and 58 percent of what they held in Syria. Before every military operation, coalition forces surround the area targeted to make sure Islamic State's foreign fighters cannot escape and make their way out of Iraq and Syria, he said. With the close cooperation of Turkish forces, the entire Syrian-Turkish border was sealed and Islamic State can no longer send militants trained in Syria for attacks in Europe and elsewhere, McGurk said. The coalition has compiled a database of almost 19,000 names of Islamic State fighters gathered from cellphones, address books and other documents found on battlefields which it is sharing with the international police agency Interpol, he said. On the military side, the northern countryside of Hama is witnessing the most violent clashes since the implementation of the de-escalation agreement, which included areas extending from the Syrian north to the Syrian south, where the activists of the Syrian Observatory monitored heavy shelling with tens of shells and missiles launched by the regime forces on areas Mork town in the northern countryside of Hama, in conjunction with heavy shelling on Lahaia village, amid heavy shelling by the regime forces on the villages of Atshan and Om Haratyen in the northeastern countryside of Hama. In Damascus, violent clashes continue between the regime forces and their allied militiamen, of Syrian and non-Syrian nationalities, on one hand and Ahmad Al-Abdu Forces and Jaysh Usud Al-Sharqiyyah on the other in Beir Mahruthah area in the southeastern part of Rif Dimashq. Clashes were accompanied by shelling by the regime forces on areas of clashes and factions-controlled areas, amid an exchange of targeting of areas of clashes between both parties. This comes as part of the factions’ attempt to advance into the area and to regain control over areas they lost during the past few weeks as a result of the successive attacks carried out by the regime forces on the area. The factions also managed to seize weapons, ammunition and vehicles. Clashes caused casualties among the regime forces and their allied militiamen.  Warplanes, whether Russian or affiliated with the International Coalition is unknown, targeted after midnight the Department of Consumer Affairs building in Thiban town in the eastern countryside of Deir Ezzor, causing material damages and destruction all over the place. No casualties have been reported so far.