Death toll from Aegean Sea quake rises in Turkey
The quake caused a mini-tsunami on the Aegean island of Samos and a sea surge that turned streets into rushing rivers in one town on Turkey's west coast.
The US Geological Survey said the 7.0 magnitude quake was registered 14 kilometres (almost nine miles) off the Greek town of Karlovasi on Samos.
Much of the damage in Turkey occurred in and around the Aegean resort city of Izmir, which has three million residents and is filled with high-rise apartment blocks.
Hospital patients on the street
Images from the popular vacation destination showed collapsed buildings and dazed survivors trying to make their way through rubbled piled high on the streets.
"Oh my God!" one passerby shouted near a collapsed building in one image that went viral in Turkey.
In another, a crowd let out a relieved cheer and broke out in applause as one woman was pulled out alive in tears.
Izmir's mayor Tunc Soyer told CNN Turk that 20 buildings had collapsed, with officials saying they were focusing their rescue efforts on 17 of them.
Turkey's disaster agency reported the death of 12 people, and said more than 400 were injured, while in Greece two teenagers died on their way home from school on Samos when a wall collapsed.
The scenes of devastation suggested the toll could rise.
One Izmir hospital rolled out some of its patients - still strapped into their beds and hooked up to drips - out on the street as a precaution.
Ali Erbas, who heads the religious affairs directorate, said mosques would open their doors to host those left homeless by the disaster.
Images on social media showed water rushing through the streets of one of the towns near Izmir from an apparent sea surge.
Thick white plumes smoke rose from various parts of the city itself, where buildings had collapsed.
Aerial footage on Turkey's NTV television showed entire city blocks turned to rubble.
Rescuers, helped by residents and sniffer dogs, used chainsaws as they tried to force their way through the rubble of a seven-floor building that had collapsed.
At one site, Agriculture Minister Bekir Pakdemirl managed to establish mobile phone contact with a girl buried under the debris.
"We ask you to remain calm," he told her in televised footage. "We will try to lift the concrete bloc and reach you."
NTV television said up to six people were trapped at the site, including the girl's cousin.
On the Greek island of Samos, near the quake's epicentre, people rushed out into the streets in panic.
"It was chaos," said deputy mayor Giorgos Dionysiou. "We have never experienced anything like this."
The Greek civil protection agency told Samos residents in a text message to "stay out in the open and away from buildings".
Greece and Turkey are both situated in one of the world's most active earthquake zones.
The two uneasy neighbours also suffer from historically poor relations despite both being members of the NATO military alliance.
But the quake saw a spurt of what pundits immediately termed "earthquake diplomacy", after Greek Prime Minister Kyriakos Mitsotakis placed a rare call to Turkish President Recep Tayyip Erdogan to offer his condolences and support.
"Whatever our differences, these are times when our people need to stand together," Mitsotakis said on Twitter.
Erdogan aide Fahrettin Altun tweeted that the disaster "reminds us once again how close we are despite our differences over policy".
France, which has feuded with Turkey over a range of regional disputes and has come under attack from Erdogan for its campaign against radical Islam, also offered its support, as did the EU and NATO.
Some of the world's strongest earthquakes have been registered along a fault line that runs across Turkey to Greece.
In 1999, a 7.4 magnitude earthquake struck Turkey's northwest, killing more than 17,000 people, including 1,000 in Istanbul.
Another quake in 2011 in the southeastern province of Van resulted in more than 600 deaths.
In Greece, the last deadly quake killed two people on the island of Kos, near Samos, in July 2017.