Seismologists predicted the kind of disaster which could happen if authorities in Izmet, near the epicentre of the disasater, did not take action, experts told the BBC.

Professor Polat Gulkan, of the Middle East Technical University, Ankara, said that he and others had given specific warnings about the safety of buildings.

Margaret Gilmore reports on the rescue efforts in one of the most unstable parts of the Earth

"I think [that the effects of this earthquake] typifies the urban sprawl in the industrial heartland of Turkey," said Professor Gulkan.

"The rate of urbanisation has been very high and unfortunately the control and supervision of the building quality has not been as good as it should be.

"Izmet is just one typical settlement that is vulnerable to earthquakes and other forms of natural disaster."

Building code

Spokesman for the Turkish embassy in London, Oran Tung: "Buildings were sub-standard"

Turkey has a strict building code which includes comprehensive regulations for ensuring that new buildings meet modern earthquake standards.

Earthquake experts at various Turkish institutions have also analysed the threat to the country's historic monuments.

But while other nations which lie on or near major fault lines have used engineering advances to reduce casualties, death tolls in Turkey have remained high.

Failings: Academics blame poor construction practices

Turkish builders have been accused of using poor quality materials as they race to build new homes for a migrating population. In Istanbul alone, which has a population of 12 million, around half of construction work is not subject to official controls.

"The quality of buildings [in Turkey] is highly variable," said Prof Gulkan.

The BBC's Pam O'Toole: "Engineers accuse some Turkish builders of using poor quality materials"

"There are buildings in many industrial or urban areas that are well designed, built and maintained and perfectly capable of withstanding a quake of this magnitude.

"But all the experts in Turkey know that there are many gaps and omissions.

"The building departments of many municipalities cannot cope with the demands for building permits and they cannot control or supervise the building process."

Deaths: Modern building techniques may have reduced toll

Dr Roger Musson, head of seismic hazards at the British Geological Survey, said that international experts knew of the risks faced by Turkey's buildings.

"There has been a lot of effort to improve the design of major structures but a lot of housing has gone up in the last 20 years without much supervision," he said.

"The buildings have been very bad and they have been put up in very dangerous places, on top of soft sediments for instance, and it is this sort of building which is going to be the nightmare.

"There is a Turkish building code which governs this but you cannot guarantee that people follow it to the letter. It is a question of economics."

"It is well known that Izmet is in a very hazardous area and has experienced several events of this magnitude or even higher," added Prof Gulkan.