21 Public anger grew as rescue teams worked frantically around the clock to try to reach victims buried in the rubble.

The BBC's Ben Brown : "It looks like a war zone"

Newspapers and commentators pointed the finger at unscrupulous land and building contractors, who they said should be held responsible for the poor quality of housing, much of which is illegal.

Even before an inquiry into the disaster had been announced, the best-selling Hurriyet newspaper was unequivocal in apportioning blame, running the headline "Murderers!"

Cheaply-built, illegal housing lies at the heart of this disaster, said engineering experts.

It accounts for why so many houses just crumpled like packs of cards and why older or more solid buildings remained intact.

Turkey's Chamber of Commerce estimates that some 65 per cent of all buildings are constructed without a permit or with scant attention to building regulations.

More than half the population in Istanbul is living in illegal accomodation, it says.

'Poor inspection system'

Professor Teymur: "Mafia have sold land to others illegally"

Professor Nezhdet Teymur, Dean of the Faculty of Architecture and Town Planning at the Middle East Technical University in Ankara, says the lack of a public housing programme and the country's poor inspection system are at the root of the sub-standard, modern housing that has been built on the edges of many cities.

He told the BBC that, while older buildings made of solid materials had remained intact, much of the modern housing in poorer urban areas was constructed from mud brick and was unable to withstand the impact of such a tremor.

A survivor carries her plates intact from the debris

The problem was compounded, he said, by the huge influx of people from rural areas into Istanbul and Izmit in search of cheap housing.

Thirty years ago, three quarters of the population lived in the countryside and a minority lived in major cities. Now, the opposite is true

This migration has encouraged a growing housing and land mafia to whom officials have turned a blind eye.

"Up to 1,000 migrants pour into Istanbul every day. Even the richest country in the world would not be able to accommodate them," said Professor Teymur.

Mafia

"When there is a high demand for land and a high demand for building, the land is provided partly illegally and then the land mafia sell it to others."

The large migrant quarters have grown on public land on the outskirts of these large cities where regulations are frequently flouted.

Contractors use the cheapest materials, says Professor Teymur, despite the fact that much of the region lies on an active faultline.

More than 20 earthquakes in Turkey in the past 75 years have exceeded 6.0 on the Richter scale, one killing 45,000 people in Erzincan in 1939.

All this should have made proper housing policies and rigorous inspection systems even more important.