As the day after Turkey and Syria’s double earthquake disaster drew to a close the death toll stood at 7,800 people—but The Economist reported earthquake expert Ovgun Ahmet Ercan as estimating that “180,000 people or more may be trapped under the rubble, nearly all of them dead”.

A breakdown of the 7,800 figure by AFP said 5,894 were confirmed dead in Turkey, while at least 1,932 were reported dead in Syria.

The World Health Organization (WHO) has warned that the final death toll could be in excess of 20,000. It has also estimated that as many as 23mn people across Turkey and Syria could have been affected by the tragedy.

As February 7 wore on, there were multiple heart-rending stories of people still trapped under rubble sending voice notes from their mobile phones appealing for a rescue team to come to their location.

Turkish President Recep Tayyip Erdogan declared as a disaster zone the 10 provinces affected by the devastating earthquakes in southeastern Turkey, imposing a state of emergency in the region for three months.

In a speech, he said 70 countries had offered help in search and rescue operations and that Turkey planned to open up hotels in the tourism hub of Antalya, to the west on the Mediterranean coast, to temporarily house homeless earthquake survivors.

In Geneva, Unicef spokesperson James Elder was reported by Reuters as telling reporters: “The earthquakes … may have killed thousands of children.”

Verified numbers were not yet available, he was cited as saying, adding that “we know that scores of schools, hospitals and other medical and educational facilities have been damaged or destroyed by the quakes, vastly impacting children”.

Describing the initial quake the most powerful to strike the region in almost 100 years, Elder said Syrian refugees in northwest Syrian and in Turkey were among the most vulnerable.

Turkey’s disaster management agency said it had 11,342 reports of buildings that collapsed during the earthquakes, of which 5,775 had been confirmed.

Turkey’s ministry of transport and infrastructure said that overnight 3,400 people took shelter in trains commandeered as emergency accommodation.

Internet monitoring group NetBlocks reported that internet connectivity had fallen further in southern Turkey and particularly in Osmaniye as authorities implemented emergency power shutdowns to support the rescue effort.

Andrew Lee, a professor of public health at the University of Sheffield in the UK, described to the Guardian the complexity involved in mounting search and rescue operations after earthquakes.

“Earthquake disasters are complex emergencies, with widespread impacts on society, infrastructure, local economies, health, education, and other sectors,” said Lee, adding: “The full scale of the disaster will not be clear for a few days yet, and the total number of casualties will probably increase. The risk of further aftershocks remains, and damaged buildings pose a further hazard.

“The consequences are not just short term but are also longer term such as through mental health effects—e.g. post-traumatic stress disorder—and the need for rehabilitation for those disabled by earthquake related injuries. The recovery from such disasters often takes many months and years afterwards.”

Lee also pointed out: “What we see in the media is only a small snapshot, and we usually won’t see affected populations and areas away from the major urban centres that media teams don’t get to.”