Aid workers are struggling to get around damaged roads, rubble and other logistical challenges to help survivors of two earthquakes in southern Turkey near the border with Syria. The quakes struck on Monday, killing at least 20,000 people.

More than 72 hours have passed since the quakes, which is said to cause a sharp drop in survival rates. But rescue teams in the two countries are still scrambling to find survivors in the rubble.

UN officials say the disaster has affected at least ten million people in Syria alone.

"Whatever we can do, we have to do it together, driven by the humanitarian needs," said El-Mostafa Benlamlih, UN Resident and Humanitarian Coordinator for Syria. "And we just hope that the political considerations and so on will get out of the way and let us do our work."

More than a decade of civil war means millions of people in northwest Syria depended on aid from across the border even before the earthquake. Those who had fled to Turkey now face an uncertain future.

"We have no hope," said a Syrian man. "We lost everything when we fled Syria. And now we've lost it all again. No home and no jobs."

Turkish President Recep Tayyip Erdogan called the earthquakes the "disaster of the century" and urged people to be patient with the progress of rescue efforts.