Desperate cries for help came from victims buried under twisted piles of concrete in the village of Celtiksuyu as weeping parents anxiously waited for rescuers to pull out the next stretcher.

The quake, measuring 6.4 on the Richter scale, hit the eastern province of Bingol at the dead of night when most people were sleeping.

It was the deadliest since 1999 when two tremors killed 20,000 people and once again shone the spotlight on shoddy building practices blamed by many for the extent of the damage.

"The number of those confirmed dead is approaching 100. The number of those injured is around 450. Rescue work is continuing, but we do not know what we will see under the rubble," Prime Minister Recep Tayyip Erdogan told reporters after a visit to the mainly-Kurdish province.

Officials earlier said 84 people were confirmed dead, 390 injured and between 150 and 200 people buried under rubble, with one minister suggesting the death toll could reach 150.

Many of the deaths occurred in Celtiksuyu, near the city of Bingol, where rescuers have so far recovered the bodies of 27 children from the wreckage of the flattened four-storey dormitory.

There was also extensive damage in Bingol city, where 10 multi-storey buildings collapsed, killing up to 45 people, while remote outlying villages reported heavy damage, with electricity and phone lines down in many places.

In Celtiksuyu, dozens of rescuers and soldiers aided by sniffer dogs dug through the wreckage of the dormitory where some 80 children were still believed to be encased under tons of concrete some 10 hours after the quake.

"We can still hear some of them screaming 'Help us. Give us water' from underneath. It is heart-breaking," one rescuer told AFP.

As relatives of the victims poured into the area, security forces were forced to cordon off the area to allow medics to treat survivors.

Of the some 200 students staying at the school, 76 had been pulled put alive by Thursday afternoon. Many were saved by their steel bunk beds which held off some of the wreckage.

"I fell into a gap between the bunk bed and the wall. This is how I survived," 14-year-old Ersin Besbelli told AFP from a makeshift bed moments after being rescued unscathed.

Amid mounting anger over the toll, Erdogan pledged to open an investigation into the company which built the boarding school. "Those who are responsible must be brought to justice. The related authorities will carry out the required investigations," he told reporters.

An angry Abdullah Gunal, father of one of the rescued children, said: "The stable that I built with my own hands did not collapse, but the school did."

Nuray Aydinoglu of the Istanbul seismological institute said proper enforcement of construction rules, tightened after the 1999 disasters, could have prevented some of the deaths.

"Unfortunately, the efficiency of engineers and construction companies that implement the projects has never been seriously taken up in Turkey," he told a press conference in Istanbul.

Offers of help came from the EU and several European countries, while the Turkish Red Crescent rushed thousands of blankets, tents, medical equipment and foodstuff to the quake-struck region.

But Erdogan said Turkey was capable of dealing with the tragedy itself.

The quake, which struck at 3:27 am (0037 GMT) and was felt in several neighbouring provinces, had its epicentre 16 kilometres (10 miles) northeast of Bingol, according to the Istanbul seismological institute.

Turkey is criss-crossed by active faultlines, including one in northern Anatolia which caused the two major quakes in August and November 1999, east of the Marmara Sea, killing 20,000.

Bingol is situated on the eastern Anatolia fault, and on May 22,1971 was rocked by a quake measuring 6.8 on the Richter scale, which claimed 900 lives.

In January this year, an earthquake with a magnitude of 6.5 struck the neighbouring province of Tunceli, killing one person and injuring several others.

SPACE.WIRE