Thousands left injured or homeless and hampering efforts to find survivors.
The magnitude 7.8 quake brought down whole apartment blocks in Turkish cities and piled more devastation on millions of Syrians displaced by years of war.
The worst tremor to strike Turkey this century came before sunrise in harsh weather and was followed in the early afternoon by another large quake of magnitude 7.7.
“It was like the apocalypse,” said Abdul Salam al-Mahmoud, a Syrian in the northern town of Atareb. “It’s bitterly cold and there’s heavy rain, and people need saving.”
The second quake was big enough to bring down more buildings and, like the first, was felt across the region, endangering rescuers struggling to pull casualties from the rubble.
In Diyarbakir in southeast Turkey, a woman speaking next to the wreckage of the seven-storey block where she lived said: “We were shaken like a cradle. There were nine of us at home. Two sons of mine are still in the rubble, I’m waiting for them.”
She was nursing a broken arm and had injuries to her face.
The earthquake was the biggest quake recorded worldwide by the U.S. Geological Survey since a tremor in the remote South Atlantic in August 2021.
In Turkey, the death toll stood at 1,541, Vice President Fuat Oktay said. At least 928 people were killed in Syria, according to figures from the Damascus government and rescue workers in the northwestern region controlled by insurgents.
Poor internet connections and damaged roads between some of the worst-hit cities in Turkey’s south, homes to millions of people, hindered efforts to assess and address the impact.
Temperatures in some areas were expected to fall to near freezing overnight, worsening conditions for people trapped under rubble or left homeless. Rain was falling on Monday after snowstorms swept the country at the weekend.
It is already the highest death toll from an earthquake in Turkey since 1999, when a tremor of similar magnitude devastated the heavily populated eastern Marmara Sea region near Istanbul, killing more than 17,000.
President Tayyip Erdogan, who is preparing for a tough election in May, called it a historic disaster and the worst earthquake to hit Turkey since 1939, but said authorities were doing all they could.
Meanwhile, countries around the world mobilised rapidly to send aid and rescue workers on Monday after the earthquake.
The European Union mobilised 10 search and rescue teams for Turkey after the stricken country requested EU assistance, EU foreign policy chief, Josep Borrell, and EU crisis management commissioner, Janez Lenarcic, said.
The EU’s Copernicus satellite system has been activated to provide emergency mapping services, it said, adding that the bloc was ready to support those affected in Syria too.
On its part, the United Nations General Assembly observed a minute of silence in tribute to the victims.
“Our teams are on the ground assessing the needs and providing assistance. We count on the international community to help the thousands of families hit by this disaster, many of whom were already in dire need of humanitarian aid in areas where access is a challenge,” UN Secretary-General, Antonio Guterres, said.
Two of India’s National Disaster Response Force teams comprising 100 personnel with dog squads and equipment were ready to be flown to the affected area, the foreign ministry said. Doctors and paramedics with medicines were also being readied.
Prime Minister Narendra Modi said he was “anguished” and “deeply pained” by the deaths in Turkey (with whom India has frosty relations) and Syria.
Reacting to the disaster, US President Joe Biden said he was “deeply saddened” by the loss of life. US teams were “deploying quickly to begin to support Turkish search and rescue efforts,” he added.
National security spokesman John Kirby said the United States was sending two search-and-rescue teams of 79 people each, while the Pentagon and USAID were coordinating with their Turkish counterparts.
President Vladimir Putin of Russia promised to send teams to both countries in telephone calls with Syria’s Bashar al-Assad and Turkey’s Recep Tayyip Erdogan.