Follow the latest on the earthquake in Turkey
A major earthquake on Monday evening has left widespread devastation across Turkey and Syria, with more than 2,600 dead.
Hundreds of buildings have been destroyed, with many people feared trapped under the rubble.
The quake and scores of aftershocks, one of which was almost as big as the original earthquake, was felt across the region in Lebanon, Cyprus and Iraq, and as far away as Greenland.
The initial quake had a 7.8 magnitude. The death toll is expected to rise sharply.
Governments and international aid groups rushed to help Turkey and Syria with emergency assistance, pledging everything from disaster rescue specialist teams to vital humanitarian aid. Turkish President Reccip Tayyip Erdogan said 45 countries had offered help with search and rescue efforts.
The UAE said it would set up a field hospital and dispatch search and rescue teams to Turkey and Syria, and would provide urgent relief to Syria's hardest hit areas.
"The UAE reiterated its solidarity with Turkey and Syria over the victims and expressed its sincere condolences to the two countries and their peoples," the country's foreign ministry said.
In Turkey, the death toll stood at 1,651, Health Minister Fahrettin Koca said, and 11,119 people were recorded as injured. At least 968 people were killed in Syria, according to figures from the Damascus government and rescue workers in the northwestern region controlled by insurgents.
Survivors in Turkey rushed out into the snow-covered streets in their pyjamas, watching rescue operations search for survivors with their hands. In northeastern Syria, terrified residents ran out of their homes after the ground shook.
Mr Erdogan acknowledged the challenge presented by the cold weather on Monday evening.
"Everyone is putting their heart and soul into efforts although the winter season, cold weather and the earthquake happening during the night makes things more difficult," he said.
Erdem, a resident of Gaziantep, a city near the quake's epicentre, said he had “never felt anything like it in the 40 years I've lived”.
“We were shaken at least three times very strongly, like a baby in a crib,” he said.
In the rebel-held north, which shares a border with Turkey, the Syrian American Medical Society (Sams) said it had to evacuate one of its hospitals in the Idlib village of Aldana, about 160km from Gaziantep, after it sustained “major damage” and was deemed unsafe.
A Sams official with the society said hospitals were overwhelmed and patients were being treated in hallways and on floors.
At least two of the society's maternity hospitals sustained damage and were evacuated, the official said.
Health officials in Hama said a child was among those killed when a three-storey building collapsed.
“Wounded people are still arriving in waves,” Aleppo's health director Ziad Hage Taha told Reuters by telephone.
The US Geological Survey said the quake struck at a depth of 17.9km.
Turkey's Disaster and Emergency Management Authority said they recorded 42 aftershocks, the strongest with a magnitude of 6.6.
Turkey declared a “level 4 alarm” and urged the world to send assistance as Mr Erdogan called the governors of eight affected provinces for an update on the situation and rescue efforts, his office said.
Mr Erdogan said on Twitter: “We hope that we will get through this disaster together as soon as possible and with the least damage.”
Syria's President Bashar Al Assad was on Monday holding an emergency cabinet meeting, his office said.
Most affected regions in northern Syria are largely under the control of rebels and extremist groups still at war with Damascus, potentially complicating aid delivery. Most aid to the area enters through the badly hit regions of Turkey.
The region straddles seismic fault lines, although Monday's quake was the strongest in about a century.
In August 1999, a 7.6-magnitude earthquake near the Turkish city of Izmit killed more than 17,100 people and injured 50,000 others.
More than 500,000 homes were destroyed, largely due to the widespread use of poor-quality building materials.
Since then, Turkey has tried to improve regulations to prevent or reduce the possibility of buildings collapsing.
Residents sifting through rubble
The scale of Monday's quake was still being determined, but in Malatya, 160km north-east of Gaziantep, authorities said at least 140 buildings had collapsed.
In Osmaniye, 95km east of Gaziantep, at least 35 buildings were flattened.
Across eastern Turkey, emergency teams worked to free people trapped beneath the rubble.
Footage broadcast by local news channels showed residents sifting through debris in the dark while awaiting emergency rescue teams.
A member of the Syrian Civil Defence rescue team, known as the White Helmets, in Salqin, near the Turkish border, called the situation “catastrophic”.
“Tens of buildings completely collapsed and there is an entire electricity blackout,” the representative said. “All the residents are out on the streets, out of fear that their buildings might collapse at any moment.”
Rescue teams were working to clear roads in Afrin after fears that heavy snow and freezing temperatures would impede relief efforts.
Rami Abdulrahman, head of the Syrian Observatory for Human Rights, said northern Syria did not have the capacity to treat the injured, “let alone perform resuscitation efforts for the fallen”.
“This is why we will be seeing the death toll rise like exponentially throughout the day,” he said.
Quake felt around the region
The earthquake was felt hundreds of kilometres away.
In the northern Iraqi city of Erbil, roads were congested as many residents sought shelter in their cars amid fears that their buildings would collapse.
In Lebanon, some residents ran out of their homes after being awakened at around 3.20am by a 4.8-magnitude aftershock.
In the south, people stood in the street in the rain. As of 7am local time, there were no reports of deaths or injuries but the National News Agency said the shocks had cracked a road in the southern city of Tyre.
In Egypt, the state geophysics institute said a series of aftershocks measured at magnitude 6 were felt in coastal cities and in Cairo, but there were no reports of casualties or damage to property.
Mohammed Safey, 40, who lives in Cairo, said he was awakened by the earthquake.
“I woke up thinking my dog was walking on top of me while I was sleeping,” he said.