Countries around the world dispatched teams to assist in the rescue efforts, and Turkey's disaster management agency said more than 24,400 emergency personnel were now on the ground.
Rescuers raced Tuesday to find survivors in the rubble of thousands of buildings brought down by a 7.8 magnitude earthquake and multiple aftershocks that struck eastern Turkiye and neighbouring Syria, with the discovery of more bodies raising the death toll to more than 5,000.
Countries around the world dispatched teams to assist in the rescue efforts, and Turkiye's disaster management agency said more than 24,400 emergency personnel were now on the ground. But with such a wide swath of territory hit by Monday's earthquake and nearly 6,000 buildings confirmed to have collapsed in Turkiye alone, their efforts were spread thin.
Attempts to reach survivors were also impeded by temperatures below freezing and close to 200 aftershocks, which made the search through unstable structures perilous.
Nurgul Atay told The Associated Press she could hear her mother's voice beneath the rubble of a collapsed building in the city of Antakya, the capital of Hatay province, but that her and others efforts to get into the ruins had been futile without any rescue crews and heavy equipment to help.
“If only we could lift the concrete slab we'd be able to reach her,” she said. “My mother is 70-years-old, she won't be able to withstand this for long.”
Across Hatay province, just southwest of the earthquake's epicentre, officials say as many as 1,500 buildings were destroyed and many people reported relatives being trapped under the rubble with no aid or rescue teams arriving.
In areas where teams worked, occasional cheers broke out through the night as survivors were brought out of the rubble.
The quake, which was centred in Turkiye's southeastern province of Kahramanmaras, sent residents of Damascus and Beirut rushing into the street and was felt as far away as Cairo.
Sebastien Gay, the head of mission in Syria for Doctors Without Borders, said health facilities in northern Syria were overwhelmed with medical personnel working around “around the clock to respond to the huge numbers of wounded.”
In Turkiye's Hatay province, thousands of people sheltered in sports centres or fair halls, while others spent the night outside, huddled in blankets around fires.
Turkiye has large numbers of troops in the border region with Syria and has tasked the military to aid in the rescue efforts, including setting up tents for the homeless and a field hospital in Hatay province.
Defence Minister Hulusi Akar said a humanitarian aid brigade based in Ankara and eight military search and rescue teams had also been deployed.
A navy ship docked on Tuesday at the province's port of Iskenderun, where a hospital collapsed, to transport survivors in need of medical care to the nearby city of Mersin.
Thick, black smoke rose from another area of the port, where firefighters have not yet been able to douse a fire that broke out among shipping containers that were toppled by the earthquake.
In the Turkish city of Gaziantep, a provincial capital about 33 kilometres (20 miles) from the epicentre, people took refuge in shopping malls, stadiums, mosques and community centres.
Turkiye's Vice President Fuat Oktay said the total number of deaths in Turkiye had passed 3,400, with some 21,000 people injured.
The death toll in government-held areas of Syria climbed over 800 people, with some 1,400 injured, according to the Health Ministry. In the country's rebel-held northwest, the opposition's Syrian Civil Defence, or White Helmets, the paramedic group leading rescue operations, said that at least 790 were killed and more than 2,200 injured.
Authorities fear the death toll will keep climbing as the rescuers look for survivors among tangles of metal and concrete spread across the region beset by Syria's 12-year civil war and refugee crisis.
In the latest pledges of international help, South Korean President Yoon Suk Yeol said he was preparing to swiftly dispatch a 60-person search and rescue team as well as medical supplies and 50 soldiers.
Pakistan's government sent a flight carrying relief supplies and a 50-member search and rescue team early Tuesday, and said there will be daily aid flights to Syria and Turkiye from Wednesday. India said it would send two search and rescue teams, including specially trained dogs and medical personnel.
Pakistani Prime Minister Shehbaz Sharif will travel to Ankara Wednesday to express his condolences and solidarity, according to a statement from Islamabad.
US President Joe Biden called Turkish President Recep Tayyip Erdogan to express condolences and offer assistance to the NATO ally. The White House said it was sending search-and-rescue teams to support Turkiye's efforts.
The quake piled more misery on a region that has seen tremendous suffering over the past decade. On the Syrian side, the affected area is divided between government-controlled territory and the country's last opposition-held enclave, which is surrounded by Russian-backed government forces. Turkiye is home to millions of refugees from the Syrian civil war.
In the rebel-held enclave, hundreds of families remained trapped in rubble, the opposition emergency organisation known as the White Helmets said in a statement. The area is packed with some 4 million people displaced from other parts of the country by the war. Many live in buildings that are were already damaged by military bombardments.
Strained medical centres quickly filled with injured people, rescue workers said. Some facilities had to be emptied, including a maternity hospital, according to the SAMS medical organisation.
More than 7,800 people were rescued across 10 provinces, according to Orhan Tatar, an official with Turkiye's disaster management authority.
The region sits on top of major fault lines and is frequently shaken by earthquakes. Some 18,000 were killed in similarly powerful earthquakes that hit northwest Turkiye in 1999.
The US Geological Survey measured Monday's quake at 7.8, with a depth of 18 kilometres (11 miles). Hours later, another quake, likely triggered by the first, struck more than 100 kilometres (60 miles) away with 7.5 magnitude.
The second jolt caused a multistory apartment building in the Turkish city of Sanliurfa to topple onto the street in a cloud of dust as bystanders screamed, according to video of the scene.
Thousands of buildings were reported collapsed in a wide area extending from Syria's cities of Aleppo and Hama to Turkiye's Diyarbakir, more than 330 kilometres (200 miles) to the northeast