A 6.8 magnitude earthquake rocked a sparsely populated part of eastern Turkey on Friday, killing at least 20 people, injuring more than 900 and leaving some 30 trapped in the wreckage of toppled buildings, Turkish officials said.
Rescue teams from neighbouring provinces were dispatched to the affected areas, working in the dark with floodlights in freezing temperatures, and Defence Minister Hulusi Akar said troops were on standby to help.
Hundreds of residents were left homeless or with damaged homes.
TV footage showed rescuers pull out one injured person from the rubble of a collapsed building in the district of Gezin in the Elazig province.
Interior Minister Suleyman Soylu said emergency workers were searching for 30 people trapped under the rubble.
The quake struck at 8:55pm local time (17:55 GMT), at a depth of 6.7km (4.1 miles) near the town of Sivrice in Elazig, the Disaster and Emergency Management Presidency, or AFAD, said. It was followed by several aftershocks, the strongest with magnitudes 5.4 and 5.1.
Elazig is some 750km (465 miles) east of the capital, Ankara.
AFD said sixteen people were killed in Elazig and four more in the neighbouring province of Malatya. Some 920 injured were in hospitals in the region, it added.
Some 30 buildings had collapsed from the quake in the two provinces, according to Murat Kurum, the environment minister.
Turkish President Recep Tayyip Erdogan said on Twitter that all measures were being taken to “ensure that the earthquake that occurred in Elazig and was felt in many provinces is overcome with the least amount of loss”.
People in Elazig whose homes were damaged or were too afraid to go indoors were being moved to student dormitories or sports centres in freezing conditions.
“Our houses collapsed … we cannot go inside them,” said a 32-year-old man from Sivrice, the epicentre of the quake.
AFAD warned residents not to return to damaged buildings because of the danger of further aftershocks. It said beds, blankets and tents were being sent to the area where some people sheltered in sports gymnasiums.
Elazig Governor Cetin Oktay Kaldirim told NTV television that a fire broke out in a building in Sivrice but was quickly brought under control.
The Kandilli seismology centre in Istanbul said the quake measured 6.5, while the US Geological Survey gave a preliminary magnitude as 6.7, and said the earthquake affected not only Turkey but also Syria, Georgia and Armenia. Different earthquake monitoring centres frequently give differing estimates.
NTV said the earthquake was felt in several Turkish provinces and sent people running outdoors in panic.
Turkey sits on top of two major faultlines and earthquakes are frequent. Two strong earthquakes struck northwest Turkey in 1999, killing around 18,000 people.
A magnitude 6 earthquake killed 51 people in Elazig in 2010.