The combined death toll in Turkey and Syria from Monday's quakes has risen to more than 11,500.
The World Health Organisation has suggested the final toll could rise as high as 20,000, and thousands are complaining about the lack of resources and slow official response.
Across a swathe of southern Turkey, people sought temporary shelter and food in freezing winter weather, and waited in anguish by piles of rubble where family and friends might still lie buried.
Rescuers were still digging out some people alive, and finding others dead. But many Turks have complained of a lack of equipment, expertise and support to rescue those trapped - sometimes even as they could hear cries for help.
"Where is the state? Where have they been for two days? We are begging them. Let us do it, we can get them out," Sabiha Alinak said near a snow-covered collapsed building where her young relatives were trapped in the city of Malatya.
Criticism from opposition figures and on the ground is growing. Some claim that emergency efforts have been too slow and that not enough was done to prepare the earthquake-prone region during his eight years in office.
Turkish President Tayyip Erdogan has visited the disaster zone and while in Hatay, one of the region's hardest hit by the quake, Erdogan responded saying: "It is not possible to be prepared for a disaster this big."
He described people saying they had not seen security forces at all in some areas as "provocateurs".
"This is a time for unity, solidarity. In a period like this, I cannot stomach people conducting negative campaigns for political interest," he added.
During another stop on his tour of areas in the disaster zone, he acknowledged some initial problems but said the situation was now "under control".
There were similar scenes and complaints in neighbouring Syria, whose north was also hard hit by Monday's huge quake.
Syria's ambassador to the United Nations admitted the government had a "lack of capabilities and lack of equipment" but blamed this on over a decade of civil war in his country and Western sanctions.
Death toll sure to rise
The death toll from both countries was expected to rise further as hundreds of collapsed buildings in many cities have become tombs for people who had been asleep in the homes when the quake hit in the early morning.
In the Turkish city of Antakya, dozens of bodies, some covered in blankets and sheets and others in body bags, were lined up on the ground outside a hospital.
Melek, 64, said she had seen no rescue teams. "We survived the earthquake, but we will die here due to hunger or cold."
Families in southern Turkey and in Syria spent a second night in the freezing cold.
Many in the disaster zone had slept in their cars or in the streets under blankets, fearful of going back into buildings shaken by the 7.8 magnitude tremor - Turkey's deadliest since 1999 - and by a second powerful quake hours later.
The reported death toll rose to 9057 in Turkey on Wednesday. In war-wrecked Syria, the confirmed toll climbed to more than 2500 overnight, according to the government and a rescue service operating in the rebel-held northwest.
Turkish authorities released video of rescued survivors, including a young girl in pyjamas, and an older man covered in dust, an unlit cigarette clamped between his fingers as he was pulled from the debris.
Turkish officials say some 13.5 million people were affected in an area spanning roughly 450km from Adana in the west to Diyarbakir in the east. In Syria, it killed people as far south as Hama, 250km from the epicentre.
'No aid has made it to rebel-held Syria' - activist
A panel news programme on a northern Syria-based TV station has painted a bleak picture of the situation there, the BBC reports.
Activist Ahmed Abu Hamza told Al-Yaum, with the exception of an "Egyptian technical team", no supplies had made it through to rebel-held Idlib province.
He said local crews would not be able to cope for more than a few days without help, adding: "There will be a catastrophe in northern Syria."
More than 1500 people are reported to have died in a region which relief agencies struggled to reach even before the earthquake.
Some of those killed in Turkey were refugees from Syria's war. Their body bags arrived at the border in taxis, run-down vans and in piles atop flatbed trucks to be taken to final resting places in their homeland.
More than 298,000 people have been made homeless and 180 shelters for the displaced had been opened, Syrian state media reported, apparently referring to areas under government control, not those held by other factions.
In Syria's Aleppo, staff at the Al-Razi hospital attended to a man with bruised eyes who said more than a dozen relatives including his father and mother were killed when the building they were in collapsed.
"We were 16 and 13 of us died. My brother, one-and-a-half-year-old niece and I got out. Thank God," he said. "My father, my mother, my brother, his wife and their four children. The wife and two kids of my brother who got out with me also died."
Turkey is working on opening two more border gates with Syria to enable flow of humanitarian aid to its earthquake-hit neighbour, Turkish Foreign Minister Mevlut Cavusoglu has said.
Speaking to reporters, Cavusoglu said damage on the Syria side of the road leading to Cilvegozu border gate, solely open for humanitarian aid as part of United Nations Security Council authorisation, is causing difficulties in quake response.
'Situation here is incredibly difficult' - ambassador in Ankara
New Zealand's ambassador in Ankara Zoe Coulson-Sinclair said the situation was incredibly difficult.
"The scale and magnitude of this disaster is really really difficult to wrap your head around, to give you a sense of the scale, the area affected by the disaster in Turkey alone is around the size of the North Island [of New Zealand]," Coulson-Sinclair said.
"Then on top of that the conditions in which the relief efforts are being delivered are just cruel - tonight is the third cold night in a row, it's the coldest week we've had so far this winter."
Turkey needed help and the international community was responding, Coulson-Sinclair said.
Delivering relief efforts across such a scale was incredibly difficult, particularly when so much infrastructure such as airports, roads and viaducts have also been damaged, she said.
There have not been any requests for consular assistance from New Zealanders in Turkey so far. The embassy remained in contact with authorities on the ground so would be alerted if authorities came into contact with any New Zealanders who did need help, she said.
- Reuters / BBC / RNZ