An earthquake has killed at least 19 people and injured 700 in Turkey and on the Greek island of Samos.
In Izmir, Turkey’s third largest city, 17 people died after the tremor.
The two people killed by the magnitude 7 quake on Samos were a teenage boy and girl found near a collapsed wall.
The epicentre of the tremor was in the Aegean Sea, 11 miles (17 km) off the coast of Turkey‘s Izmir province, at a depth of 10 miles (16km).
The shock was felt across the region, including in Istanbul, the Greek islands, and as far as the Greek capital Athens and also in Bulgaria.
Water surged into the Seferihisar district south of Izmir, the city home to around 4.5 million people and worst hit by the earthquake.
In Izmir, witnesses said people poured onto the streets in panic following the quake. The city’s mayor said nearly 20 buildings had collapsed.
Turkey’s health minister Fahrettin Koca said that 38 ambulances, two helicopters and 35 medical rescue teams were involved in the operation.
Footage from the area showed flattened buildings and survivors being pulled from the rubble by emergency workers.
Izmir’s governor said 70 people had been rescued from the ruins.
Student Ilke Cide said he went inland after waters rose following the quake.
“I am very used to earthquakes… so I didn’t take it very seriously at first,” he said.
“But this time it was really scary.”
A tsunami warning has been issued, with residents on the nearby Greek island of Samos, which has a population of about 45,000, told to stay away from the coast.
Water rose above the dock in the main harbour of Samos and flooded the street, and residents were also told to stay away from buildings as aftershocks rattled the area.
Local officials reported damage to buildings and part of the popular holiday island’s road network. Nineteen people were reported injured, with two being airlifted to Athens and seven taken to hospital on the island.
The two teenage victims were pronounced dead after being found unconscious in the town of Vathy.
Samos’ vice-mayor George Dionysiou said: “We have never experienced anything like it. People are panicking.”
In a statement, UK Foreign Secretary Dominic Raab said he is “deeply distressed by the scenes of destruction” caused by the earthquake.
“We stand ready to support our Turkish and Greek friends in any way they need,” he said.
Greek seismologist Efthymios Lekkas described the tremor as a “very big earthquake”, adding that it was “difficult to have a bigger one”.
On Twitter, Greek Prime Minister Kyriakos Mitsotakis said he had called Turkish President Recep Tayyip Erdogan to offer condolences over the death toll in Izmir.
“Whatever our differences, these are times when our people need to stand together,” he tweeted.
The president of the European Council, Charles Michel, said the EU also “stands ready to provide support”.
“Closely following the developments of the strong earthquake that hit the Aegean Sea off Greece and Turkey. My thoughts are with all the people affected. EU stands ready to provide support,” he tweeted.
Crisscrossed by major fault lines, Turkey is among the most earthquake-prone countries in the world.
More than 17,000 people were killed in August 1999 when a 7.6 magnitude quake struck Izmit, a city southeast of Istanbul.
In 2011, a quake in the eastern city of Van killed more than 500.