By Dasha Afanasieva KILIS, Turkey (Reuters) - The busy market district of Kilis in southeast Turkey is full of Syrian refugee children, repairing household goods, serving baklava and selling jewelery to become the main breadwinner of their families because their parents struggle to find jobs. The civil war in neighboring Syria has killed more than 140,000 people and driven 2.5 million abroad, at least 700,000 of whom have been formally registered in Turkey under its "open door" policy reflecting support for the Syrian uprising. But the total number of Syrians in Turkey is believed to be much higher and the influx has transformed the southern borderlands, with many Syrian grocery shops selling all their home brands and property prices sky-rocketing. Only 14 percent of Syrian children living outside the camps go to school, according to Turkey's Disaster and Emergency Management Directorate (AFAD), with the majority taking up work, however minimally paid, to help sustain their families.