ANTAKYA, Turkey (UPDATE)- Turkish President Recep Tayyip Erdogan on Wednesday conceded "shortcomings" after criticism of his government's response to the massive earthquake that killed over 12,000 people in Turkey and Syria.
The sprawling scale of the disaster that flattened thousands of buildings, trapping an unknown number of people, has swamped relief operations already hampered by freezing weather.
Survivors have been left to scramble for food and shelter -- and in some cases watch helplessly as their relatives called for rescue, and eventually went silent under the debris.
"My nephew, my sister-in-law and my sister-in-law's sister are in the ruins. They are trapped under the ruins and there is no sign of life," said Semire Coban, a kindergarten teacher, in Turkey's Hatay.
"We can't reach them. We are trying to talk to them, but they are not responding... We are waiting for help. It has been 48 hours now," she said.
Still, searchers kept pulling survivors from the debris three days after the 7.8 magnitude quake that is already one of the deadliest this century, even as the death toll continues to rise.
As criticism mounted online, Erdogan visited one of the hardest-hit spots, quake epicenter Kahramanmaras, and acknowledged problems in the response.
"Of course, there are shortcomings. The conditions are clear to see. It's not possible to be ready for a disaster like this," he said.
Twitter was also not working on Turkish mobile networks, according to AFP journalists and NetBlocks web monitoring group.
The window for rescuers to find survivors is narrowing as the effort nears the 72-hour mark that disaster experts consider the most likely period to save lives.
Yet on Wednesday, rescuers pulled children from under a collapsed building in the hard-hit Turkish province of Hatay, where whole stretches of towns have been levelled.
"All of a sudden we heard voices and thanks to the excavator... immediately we heard the voices of three people at the same time," said rescuer Alperen Cetinkaya.
"We are expecting more of them... the chances of getting people out of here alive are very high," he added.
Officials and medics said 9,057 people had died in Turkey and 2,992 in Syria from Monday's 7.8-magnitude tremor, bringing the total to 12,049 -- but that could yet double if the worst fears of experts are realized.
The World Health Organization chief Tedros Adhanom Ghebreyesus has warned that time was running out for the thousands injured and those still feared trapped.
'PEOPLE DYING EVERY SECOND'
Due to the scale of the damage and the lack of help coming to certain areas, survivors said they felt alone in responding to the disaster.
"Even the buildings that haven't collapsed were severely damaged. There are now more people under the rubble than those above it," a resident named Hassan, who did not provide his full name, said in the rebel-held town of Jindayris.
"There are around 400-500 people trapped under each collapsed building, with only 10 people trying to pull them out. And there is no machinery," he added.
The White Helmets, leading efforts to rescue people buried under rubble in rebel-held areas of Syria, have appealed for international help in their "race against time".
They have been toiling since the quake to pull survivors out from under the debris of dozens of flattened buildings in northwestern areas of war-torn Syria that remain outside the government's control.
"International rescue teams must come into our region," said Mohammed Shibli, a spokesperson for the group known formally as the Syria Civil Defense.
"People are dying every second; we are in a race against time," he told AFP from neighboring Turkey.
SYRIA APPEALS FOR EU HELP
The issue of aid to Syria was a delicate one, and the sanctioned government in Damascus made an official plea to the EU for help, the bloc's commissioner for crisis management Janez Lenarcic said.
A decade of civil war and Syrian-Russian aerial bombardment had already destroyed hospitals, collapsed the economy and prompted electricity, fuel and water shortages.
The European Commission is "encouraging" EU member countries to respond to Syria's request for medical supplies and food, while monitoring to ensure that any aid "is not diverted" by President Bashar al-Assad's government, Lenarcic noted.
Dozens of nations, including the United States, China and the Gulf States have pledged to help, and search teams as well as relief supplies have already arrived.
A winter storm has compounded the misery by rendering many roads -- some of them damaged by the quake -- almost impassable, resulting in traffic jams that stretch for kilometers in some regions.
The European Union was swift to dispatch rescue teams to Turkey after the massive earthquake struck the country on Monday close to the border with Syria.
But it initially offered only minimal assistance to Syria through existing humanitarian programs, because of EU sanctions imposed since 2011 on Assad's government over its brutal crackdown on protesters that spiraled into a civil war.
The Turkey-Syria border is one of the world's most active earthquake zones.
Monday's earthquake was the largest Turkey has seen since 1939, when 33,000 people died in the eastern Erzincan province.
In 1999, a 7.4 magnitude earthquake killed more than 17,000.