VAN, Turkey (Reuters) - As many as 1,000 people were feared killed on Sunday when a powerful earthquake hit southeast Turkey, flattening buildings and leaving survivors crying for help from under the rubble.
As night fell, survivors and emergency workers battled to pull people out of the debris in the city of Van and town of Ercis, where a student dormitory collapsed.
Residents in Van joined in a frantic search, using hands and shovels and working under floodlights and flashlights, hearing voices of people buried alive calling from under mounds of shattered concrete in pitch darkness and bitter cold.
An official at the Van provincial crisis center told Reuters more than 100 people had been confirmed killed so far and hundreds more were missing under destroyed buildings.
More accounts of dead bodies and destruction were emerging from smaller settlements across the remote area near the Iranian border, most of them left without electricity or phone access.
"The death toll is rising. Rescue teams are taking out dead bodies all the time," Reuters photographer Osman Orsal said in Ercis, a town of 100,000 some 100 km (60 miles) north of Van where a student dormitory collapsed.
In Van, an ancient city on a lake ringed by snow-capped mountains and with a population of 1 million, cranes were used to shift the rubble of a crumpled six-storey apartment block where bystanders reckoned there were around 70 people trapped.
"We heard cries and groaning from underneath the debris, we are waiting for the rescue teams to arrive," Halil Celik told Reuters as he stood beside the ruins of a building that had collapsed before his eyes.
"All of a sudden, a quake tore down the building in front of me. All the bystanders, we all ran to the building and rescued two injured people from the ruins."
At another site, three teenagers were believed trapped under a collapsed building. People clambered over the masonry, shouting: "Is there anyone there?"
An elderly rescue worker sat sobbing, his exhausted face covered in dust. Police tried to keep onlookers back. Ambulance crews sat waiting to help anyone dragged out of the debris.
There were reports of more bodies being pulled from rubble in hamlets outside Van. One village chief told NTV broadcaster: "Nobody has reached us, we have received no medical aid, the tents they sent are plain canvas. We are freezing."
No information was available on the fate of a 10th century Armenian church on Akdamar Island -- one of the last relics of Armenian culture in Turkey, which was recently reopened by the government as a peace gesture toward Armenia.
Kandilli Observatory general manager Mustafa Erdik told a news conference he estimated hundreds of lives had been lost. "It could be 500 or 1,000," he added. He said he based his estimate on the 7.2 magnitude of the earthquake, the strongest since 1999, and the quality of construction.
A nurse at a public hospital in Ercis said hospital workers were attending the wounded in the hospital garden because the building was badly damaged.
"We can't count dead or injured because we're not inside the hospital. There should be more than 100 dead bodies left next to the hospital. We left them there because it's dark and we didnt want to step on bodies," Eda Ekizoglu told CNN Turk television.
Prime Minister Tayyip Erdogan went by helicopter from Van to Ercis to see firsthand the scale of devastation. The cabinet was expected to discuss the quake on Monday morning.
"A lot of buildings collapsed, many people were killed, but we don't know the number. We are waiting for emergency help, it's very urgent," Zulfukar Arapoglu, mayor of Ercis, told news broadcaster NTV.
"We need tents urgently and rescue teams. We don't have any ambulances, and we only have one hospital. We have many killed and injured."
Turkey's Red Crescent said one of its teams was helping to rescue people from a student residence in Ercis. It had sent 1,200 tents, more than 4,000 blankets, stoves and food supplies, along with two mobile bakeries.
More than 70 aftershocks rocked the area, further unsettling residents who ran into the streets when the initial quake struck. Television pictures showed rooms shaking and furniture toppling as people ran from one building.
Students gathered around a camp fire in Van's center and told journalists bread prices on the black market had more than quadrupled. Dazed survivors wandered past vehicles crushed by falling masonry.
Anatolian news agency reported that 200 prisoners escaped from Van's prison after the quake, but 50 returned after seeing their familes.
Turkish media said phone lines and electricity had been cut. The quake's epicentre was at the village of Tabanli, 20 km north of Van city, Kandilli said.
International offers of aid poured in from NATO, China, Japan, the United States, Azerbaijan, European countries and Israel, whose ties with Ankara have soured since Israeli commandoes killed nine Turks during a raid on an aid flotilla bound for the Israeli-blockaded Gaza Strip in 2010.
Serzh Sarksyan, the president of Turkey's longtime regional rival Armenia, phoned Turkey's President Abdullah Gul to offer his condolences.
Major geological fault lines cross Turkey and there are small earthquakes almost daily. Two large quakes in 1999 killed more than 20,000 people in northwest Turkey.
An earthquake struck Van province in November 1976, with 5,291 confirmed dead. Two people were killed and 79 injured in May when an earthquake shook Simav in northwest Turkey.
Additional reporting by Seda Sezer, Ece Toksabay and Seyhmus Cakan, writing by Ibon Villelabeitia and Daren Butler; editing by Andrew Roche